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‡ Drs Liang and Dhoble contributed equally to this article.
Yafen Liang
Correspondence
Corresponding author: Dr. Yafen Liang, Department of Anesthesiology, McGovern Medical School, The University of Texas Health Science Center at Houston, 6431 Fannin St, MSB 5.020, Houston, Texas 77030, USA. Tel.: +1-713-500-6222 or +1-713-500-6114.
‡ Drs Liang and Dhoble contributed equally to this article.
Affiliations
Department of Anesthesiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
‡ Drs Liang and Dhoble contributed equally to this article.
Abhijeet Dhoble
Footnotes
‡ Drs Liang and Dhoble contributed equally to this article.
Affiliations
Department of Cardiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Anesthesiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Cardiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Anesthesiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Anesthesiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Cardiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Cardiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Cardiac Surgery, The University of Texas Health Science Center at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Cardiac Surgery, The University of Texas Health Science Center at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Advanced Cardiopulmonary Therapies and Transplantation, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Advanced Cardiopulmonary Therapies and Transplantation, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Department of Anesthesiology, The University of Texas at Houston, McGovern Medical School/Memorial Hermann Heart and Vascular Institute, Houston, Texas, USA
Perioperative complications of transcatheter aortic valve replacement (TAVR) are decreasing but can be catastrophic when they occur. Systematic reports of the nature of these events are lacking in the contemporary era. Our study aimed to report the incidence, outcomes, and perioperative management of catastrophic cardiac events in patients undergoing TAVR and to propose a working strategy to address these complications.
Methods
This is a retrospective cohort study of patients who developed catastrophic cardiac events during or immediately after TAVR between 2015 and 2019 at a single academic centre.
Results
Of 2102 patients who underwent TAVR, 51 (2.5%) developed catastrophic cardiac events. The causes included cardiac perforation and tamponade (n = 19, 37.3%), acute left- ventricular failure (n = 10, 19.6%), coronary artery obstruction (n = 10, 19.6%), aortic-root disruption (n = 7, 13.7%), and device embolization (n = 5, 9.8%). Twenty-four patients (47.0%) with catastrophic cardiac events required stabilization by either intra-aortic balloon counter-pulsation or extracorporeal membrane oxygenation. The in-hospital mortality rate increased by 11.7-fold for patients with catastrophic cardiac events compared with those without (25.5% vs 2.0%, P < 0.001). Patients who developed aortic root disruption had the highest mortality rate (42.8%) compared with the others. The incidence of catastrophic cardiac events remained stable over a 5-year period, but the associated mortality decreased from 38.5% in 2015 to 9.1% in 2019.
Conclusions
Catastrophic cardiac events during TAVR are rare, but they account for a dramatic increase in perioperative mortality. Early recognition and development of a standardized perioperative team approach can help manage patients experiencing these complications.
Résumé
Contexte
Les complications périopératoires d'un remplacement valvulaire aortique par cathéter (RVAC) diminuent, mais peuvent être catastrophiques lorsqu'elles surviennent. À l’époque actuelle, il n'y a pas de rapports systématiques sur la nature de ces événements. Notre étude visait à faire connaître la fréquence, l'issue et la prise en charge périopératoire des événements cardiaques catastrophiques chez des patients qui subissent un RVAC et à proposer une stratégie de travail pour remédier à ces complications.
Méthodologie
Il s'agit d'une étude de cohorte rétrospective portant sur des patients ayant présenté des événements cardiaques catastrophiques pendant ou immédiatement après un RVAC, entre 2015 et 2019, à un seul centre hospitalier universitaire.
Résultats
Parmi les 2 102 patients qui ont subi un RVAC, 51 (2,5 %) ont présenté des événements cardiaques catastrophiques. Les causes comprenaient une perforation du cœur et une tamponnade (n = 19; 37,3 %), une insuffisance ventriculaire gauche aiguë (n = 10; 19,6 %), une obstruction de l'artère coronaire (n = 10; 19,6 %), une déchirure de la racine de l'aorte (n = 7; 13,7 %) et l'embolisation d'un dispositif (n = 5; 9,8 %). Il a fallu stabiliser l’état de 24 patients (47,0 %) présentant des événements cardiaques catastrophiques en ayant recours à la contre-pulsion par ballonnet intra-aortique ou à l'oxygénation extracorporelle. Le taux de mortalité hospitalière a augmenté de 11,7 fois chez les patients présentant des événements cardiaques catastrophiques par rapport à ceux qui n'en présentaient pas (25,5 % vs 2,0 %; p < 0,001). Le taux de mortalité était le plus élevé (42,8 %) chez les patients présentant une déchirure de la racine de l'aorte que chez les autres patients. La fréquence des événements cardiaques catastrophiques est demeurée stable sur une période de cinq ans, mais le taux de mortalité associé a diminué pour passer de 38,5 % en 2015 à 9,1 % en 2019.
Conclusions
Les événements cardiaques catastrophiques survenant pendant un RVAC sont rares, mais ils entraînent une augmentation spectaculaire de la mortalité périopératoire. La reconnaissance précoce et l’élaboration d'une approche normalisée d’équipe périopératoire peuvent contribuer à la prise en charge des patients présentant ces complications.
Transcatheter aortic valve replacement (TAVR) has gained widespread use in the United States and Europe;
Complications after transfemoral transcatheter aortic valve replacement with a balloon-expandable prosthesis: the importance of preventative measures and contingency planning.
Intraprocedural catastrophic cardiac events, including annular rupture, device embolization, coronary artery obstruction, acute left ventricular failure, and tamponade, are rare but can be life threatening. These events have been associated with a 30-day mortality rate of up to 50% when emergent cardiac surgery was required to manage these complications.
Predictors and outcomes after transcatheter aortic valve implantation using different approaches according to the valve academic research consortium definitions.
Previous studies have focused on identifying the etiologies and predictors of these events as well as examining intraprocedural approaches to prevent such events from occurring.
Multiple studies highlight the importance of a team consisting of interventional cardiologists, cardiac surgeons, and cardiac anesthesiologists in managing these events.
However, because of the rarity and unpredictability of such events, a systemic perioperative management approach has not been proposed previously. Therefore, we conducted a retrospective review of a large, single-centre experience of catastrophic cardiac events during TAVR and the emergency management measures that were used. Based on this experience, we are proposing an algorithm for early differential diagnosis and perioperative management of catastrophic events during TAVR.
Materials and Methods
Study design and data collection
This is a single-centre retrospective cohort study of patients who developed catastrophic cardiac events during or immediately after TAVR procedures. Approval was obtained from the Institutional Review Board (IRB) of University of Texas Health Science Center, Houston, Texas. As this was a retrospective observational study, informed consent was waived by the IRB.
Catastrophic cardiac events were defined as an episode of significant hemodynamic or electrical instability during the valvular perideployment period, with or without the requirement of cardiopulmonary resuscitation. All patients’ procedural and follow-up data were entered into the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy (TVT) Registry by qualified research personnel. For the current study, the database was screened for all adverse events by 2 experienced physicians (Y.L., A.P.). All patients who were identified to have experienced perioperative myocardial infarction, coronary obstruction, cardiac arrest, annular rupture, aortic dissection, cardiac perforation and tamponade, perioperative device migration or embolization, or unplanned cardiac surgery were selected for further investigation. The medical records, fluoroscopic images, and echocardiograms of each patient were carefully reviewed to identify the etiology of hemodynamic instability, and the subsequent management details were also reviewed.
Patient population and perioperative management
Patients undergoing TAVR between January 2015 and December 2019 were selected for the study to reflect contemporary practice. All TAVR procedures were performed in either a hybrid cardiac catheterization laboratory or an operating suite. The catheterization lab used for TAVRs at our institution is a hybrid suite in which cannulation and conversion from closed to open chest can be accomplished immediately, without the need to transfer the patient to the operating suite. Patients were also prepped and draped adequately for immediate open-chest surgical exploration.
An interventional cardiologist and a cardiovascular surgeon performed the procedure together. Cardiac anesthesiologists provided anesthesia and assisted in resuscitation during catastrophic events. There was an active collaboration between the cardiologist and the cardiac surgeon throughout the case, especially during periods of major decision making. The majority of cardiac surgeons were scrubbed in during critical moments of the case, including the deployment phase of the valve and removal of the large valve insertion sheath. In addition, an intra-aortic balloon pump (IABP), perfusionist, and a prepared extracorporeal membrane oxygenation (ECMO) machine were available in the room.
As an institutional policy, in the event of acute hemodynamic instability, patients were supported with vasopressor and volume resuscitation while undergoing diagnostic and treatment measures. If the patient developed precipitous hemodynamic collapse, unresponsive to conservative measures, or developed ventricular arrhythmia that required advanced cardiac life support (ACLS refers to a group of procedures to treat cardiac arrest and other life-threatening medical emergencies; this includes defibrillation, airway management, and use of medications to restore spontaneous heart rhythm and organ perfusion), mechanical circulatory support (MCS) was used for immediate stabilization.
Statistical analysis
All results are presented as mean ± standard deviation or median (interquartile range) for continuous variables depending on the variable distribution. Categorical variables are presented as numbers (frequency). Continuous variables were compared with a Student's t-test or Mann–Whitney test if data were skewed, whereas categorical variables were compared by a Fisher's exact test or a χ2 test, as appropriate. Statistical analysis was performed with STATA Version/IC 14.2 (StataCorp LLC, College Station, TX).
Results
Patient and procedure characteristics
During the study period, a total of 2102 patients underwent TAVR at our institution. The mean age of the cohort was 78.4 years, and the median Society of Thoracic Surgery (STS) score was 7% for the risk of mortality. The majority of patients underwent TAVR via the transfemoral approach (n = 2041, 97.4%) and received local anesthetic infiltration of the access sites with intravenous sedation compared with general anesthesia (68.7% vs 31.3%). A total of 51 patients (2.5%) experienced periprocedural catastrophic cardiac events. Patient demographics and baseline characteristics are summarized in Table 1, and procedural data are summarized in Table 2.
Table 1Patient characteristics (n = 2102)
Total patients (n = 2102)
Hemodynamic collapse (n = 51)
No hemodynamic collapse (n = 2051)
P value
Age, years
78.4 ± 9.4
78.6 ± 9.4
78.4 ± 9.4
0.88
Female sex
1010 (48.1%)
33(64.7%)
977 (47.5%)
0.02
Height, cm
167.2 ± 12.1
164.0 ± 10.0
167.3 ± 12.2
0.06
Weight, kg
81.9 ± 22.2
72.8 ± 21.3
82.1 ± 22.2
0.00
BMI, kg/m2
27.9 (24.3, 33.0)
25.6 (21.4, 33.3)
27.9 (24.4, 33.0)
0.05
Current smoker
156 (7.5%)
0 (0%)
156 (7.6%)
0.04
Hypertension
1998 (95.2%)
48 (94.1%)
1950 (95.3%)
0.70
Diabetes
888 (42.5%)
15 (29.4%)
873 (42.8%)
0.05
Renal insufficiency on hemodialysis
126 (6.0%)
5 (9.8%)
121 (5.9%)
0.25
Peripheral artery disease
856 (41.0%)
23 (45.1%)
833 (40.8%)
0.54
Cerebrovascular disease/TIA
147 (7.1%)
1 (2.0%)
146 (7.2%)
0.15
Previous stroke
185 (8.8%)
5 (9.8%)
180 (8.8%)
0.88
Previous MI
313 (14.9%)
8 (15.7%)
305 (14.9%)
0.88
Previous PCI
586 (28.0%)
17 (33.3%)
569 (27.9%)
0.39
Previous CABG
403 (19.3%)
9 (17.6%)
394 (19.3%)
0.77
Baseline creatinine, mg/dL
1.14 (0.9, 1.5)
1.24 (0.87, 1.7)
1.14 (0.9, 1.5)
0.42
Baseline Hb, g/dL
11.8 ± 2.1
11.3 ± 1.6
11.8 ± 2.1
0.12
STS score
7 (4.1, 10.7)
9.2 (4.4, 13.5)
7 (4.1, 10.6)
0.10
BMI, body mass index; CABG, coronary artery bypass graft; Hb, hemoglobin; MI, myocardial infarction; PCI, percutaneous coronary intervention; STS, Society of Thoracic Surgeons; TIA, transient ischemic accident.
Etiology, presentation, and management of catastrophic cardiac events
Cardiac perforation and tamponade
A total of 19 (37.3%) patients with catastrophic cardiac events experienced cardiac perforation and tamponade. These patients presented with hemodynamic collapse without concurrent electrocardiographic (ECG) changes. A diagnosis of cardiac tamponade was made using immediate echocardiography or ventriculography. For these patients, a pericardiocentesis was usually attempted first to stabilize patients while the anesthesiologist continued supportive measures. However, if patients presented with precipitous hemodynamic collapse, immediate open-chest surgery or cannulation for ECMO was performed.
Of these 19 patients, 15 underwent emergency pericardiocentesis, 6 underwent ECMO stabilization, either before or after pericardiocentesis, caused by persistent circulatory collapse, and 7 patients underwent surgical intervention. Of the 7 patients who underwent emergency surgical intervention, 4 had left-ventricular (LV) perforation repair, and 3 had right-ventricular (RV) perforation repair. The source of perforation was unidentifiable in the remaining 12 patients, as the majority of them improved with pericardiocentesis, and no surgical exploration was performed. A total of 5 patients did not survive to discharge, accounting for an overall in-hospital mortality rate of 26.3% in patients with cardiac perforation and tamponade during TAVR.
Coronary obstruction
Ten patients (19.6%) with catastrophic cardiac events experienced acute coronary artery obstruction. They presented with hemodynamic collapse and acute ST changes during TAVR. A diagnosis of coronary artery obstruction was obtained by immediate coronary angiography after noticing ST changes or hemodynamic collapse. The general principle of managing these events was to attempt percutaneous coronary intervention (PCI) before consideration of open surgical intervention. Depending on how severely and how rapidly patients deteriorated, they were placed on IABP or ECMO for stabilization while a more definitive treatment strategy was performed.
Among these 10 patients, 4 patients underwent preemptive placement of an undeployed coronary stent before valve deployment because the preoperative computed tomography (CT) angiography suggested an increased risk of coronary occlusion during valve deployment. The stent could then be deployed in the event of the left main obstruction. Two of these patients had calcific debris that embolized to the left main so the stent was not protective, and 2 had distal migration of the stent resulting in ostia obstruction by the new valve or old valve leaflet debris. In addition to these 4 patients who had preemptive stents to the left main artery, 4 patients unexpectedly developed acute left-anterior descending (LAD) coronary artery obstruction, and 2 patients unexpectedly developed acute right-coronary artery (RCA) occlusion. Eight of these 10 patients who received a combination of aspiration thrombectomy, balloon angioplasty, or stent placement improved and stabilized afterward, with no additional treatment needed. One patient did not improve and required a surgical coronary artery bypass graft (CABG). One patient who had left main obstruction did not receive PCI immediately because of a patent left internal mammary artery graft to the LAD. For the 8 patients who received PCI, 2 patients stabilized with IABP support, whereas the remaining 6 patients received ECMO support during the PCI. A total of 3 patients in this cohort did not survive to discharge, accounting for an overall in-hospital mortality of 30.0% in patients with acute coronary artery obstruction during TAVR.
Acute LV failure
Ten patients (19.6%) with catastrophic cardiac events experienced acute LV failure perivalve deployment. They presented with hemodynamic collapse with or without ventricular arrhythmia. A diagnosis of ventricular failure was obtained by immediate echocardiography. Ventricular failure was most frequently caused by prolonged rapid ventricular pacing in patients with pre-existing compromised LV function or significant para- or intravalvular leak after valve deployment. Five of these patients developed ventricular fibrillation, 1 patient developed sustained ventricular tachycardia, and 4 patients presented as pulseless electrical activity (PEA arrest refers to a clinical condition characterized by the lack of a palpable pulse in the presence of organized cardiac electrical activity). Six patients with ventricular arrhythmia were successfully defibrillated. In the 4 patients who experienced PEA, 2 recovered after chest compression and chemical resuscitation, and the remaining 2 patients required ECMO temporization. No patient required surgical intervention, and this entire patient cohort survived to discharge.
Aortic root disruption
Seven patients (13.7%) with catastrophic cardiac events experienced acute aortic-root disruption. They presented with hemodynamic collapse with no concurrent ECG changes after valve deployment. A diagnosis of acute aortic root disruption was obtained by immediate echocardiography (demonstrating pericardial effusion, root swelling, myocardial staining, or aortic dissection) or aortography (demonstrating extravasation of contrast). The clinical decision making of management toward these events was based on the clinical presentation. A small annulus rupture or leak can potentially be managed with an additional valve-in-valve technique and conservative therapy. However, patients with major annulus or root injury frequently present with severe hemodynamic instability requiring immediate surgical repair or stabilization with ECMO.
The site of perforation or rupture was identified as the annulus for 6 patients and the ascending aorta in the final patient. Four of these 7 patients underwent pericardiocentesis and ECMO, 1 had ECMO without pericardiocentesis, and 2 patients underwent emergency surgical intervention. A total of 3 patients did not survive to discharge in this group, including both surgical patients. This resulted in an overall in-hospital mortality of 42.8% in patients with aortic-root disruption during TAVR.
Device embolization
Five patients (9.8%) with catastrophic cardiac events experienced acute valve embolization after deployment. They developed hemodynamic collapse without acute ECG changes. Three of these patients lost capture of rapid ventricular pacing at the time of deployment, resulting in the valve being ejected and embolizing distally. A diagnosis of device embolization was obtained by immediate fluoroscopy or echocardiography. All of them initially underwent attempted endovascular device retrieval, but only 2 of them were retrieved successfully. In the 2 patients whose valves embolized into the ascending aorta, we were able to pull the embolized valves into the descending aorta and subsequently deployed the valves in this position. Second valves were then deployed in the aortic valve position. The valves that could not be retrieved or repositioned endovascularly required surgical intervention. One patient had retrieval of the TAVR valve, which was obstructing the LVAD inflow graft and AVR. One patient had valve removal from the transverse arch under circulatory arrest, and the final patient had retrieval of the valve from the left ventricle. Two of these 3 surgical patients required ECMO support for temporary stabilization before surgical retrieval. A total of 2 patients did not survive to discharge, accounting for overall in-hospital mortality of 40% for device embolization during TAVR.
Use of mechanical circulatory support
Twenty-one (41.2%) patients with catastrophic cardiac events required stabilization by ECMO in the immediate perioperative period. Among the 12 patients with a clearly documented period from cardiac arrest to ECMO cannulation, the median time was 9 minutes (range: 2 to 41 minutes). Fifteen of them required temporary intraoperative support and were successfully weaned off ECMO and decannulated either in the catheterization laboratory or the intensive care unit (ICU) shortly after TAVR procedure. Six of them required prolonged support (median 4 days, range: 1 to 14 days). ECMO was used for various etiologies of cardiac collapse, as described in detail in the previous sections. Among the 6 patients who required prolonged support, 4 patients did not survive to hospital discharge. A total of 2 patients requiring IABP support after coronary occlusion were successfully weaned off within 24 hours and were eventually discharged home.
Emergency cardiac surgery
For the 11 patients who had emergent surgical intervention, 5 patients underwent repair without cardiopulmonary bypass (CPB). In the other 6 patients, the mean CPB time was 158 minutes, with the mean aortic cross-clamp time of 121 minutes. Those patients required 9.4 (range: 0 to 44) units of packed red blood cell transfusions during surgery and 11.7 (range: 0 to 48) units total for the initial 24 hours. The in-hospital mortality for patients undergoing emergent cardiac surgery was 54.5%.
Airway management
The majority of TAVRs at our institution are performed under sedation, without an advanced airway device such as an endotracheal tube. Among sedated patients who experienced catastrophic cardiac events (25 patients in total), intubation was performed in 40% (10 patients) following catastrophic events. Specifically, 6 patients were intubated for coronary artery obstruction, 2 for annulus rupture, 1 for device embolization, and 1 for acute ventricular failure. Among the 10 patients, 5 experienced ventricular fibrillation, and 2 experienced PEA arrest requiring ACLS.
Outcomes following catastrophic cardiac events
For the 51 patients who developed catastrophic cardiac events, the in-hospital mortality was 25.5% (n = 13), which is 11.7-fold higher than patients who did not develop such events (2.0%, P < 0.001). They also had a 12.6-fold increase in the median ICU length of stay (LOS), 1.7-fold increase in the median hospital LOS, and 12.7-fold increased risk of new-onset renal failure requiring hemodialysis (all P < 0.001, Table 3). The 30-day mortality of patients with catastrophic cardiac events was 21.6%, and 1-year mortality was 39.2%. Among the 38 patients who survived to discharge, 25 were discharged to home and 13 were discharged to long-term care facilities (Table 3). The incidence of catastrophic cardiac events remained relatively stable over the 5-year study period. However, the mortality rate decreased from 38.5% in 2015 to 9.1% in 2019 (P = 0.1) (Fig. 1).
Table 3In hospital outcome of the study cohort
Total patients (n = 2102)
Hemodynamic collapse (n = 51)
No hemodynamic collapse (n = 2051)
P value
Hospital mortality
54 (2.6%)
13 (25.5%)
41 (2.0%)
0.000
ICU LOS, hours
6 (1.8, 40.3)
77.6 (35.8, 153.7)
5.7 (1.7, 35.5)
0.0000
Hospital LOS, days
3 (1, 8)
8 (4, 18)
3 (1, 8)
0.0000
Procedure to discharge time, days
2 (1, 4)
6 (3, 12)
2 (1, 4)
0.0000
New-onset HD
15 (0.76%)
4 (7.8%)
11 (0.57%)
0.000
Discharge to facility
248 (11.9%)
13 (25.5%)
235 (11.5%)
0.000
Discharge to home
1800(85.6%)
25 (49.0%)
1775 (86.5%)
0.000
HD, hemodialysis; ICU, intensive care unit; LOS, length of stay.
Figure 1Incidence of cardiac catastrophic events and associated mortality rate for the year 2015 to 2019. The figure demonstrates that the incidence of catastrophic cardiac events remained relatively stable over the 5-year study period; however, the mortality rates decreased remarkably from 38.5% in 2015 to 9.1% in 2019. TAVR, transcatheter aortic valve replacement.
Further analysis focusing on identifying the potential reason for improved outcome over time for patients experiencing catastrophic cardiac events revealed that patients’ median and interquartile range of STS score decreased from 8.8 (5.7, 12) in 2015 to 5.4 (3.3, 9.1) in 2019. In addition, complications with a higher mortality rate such as device embolization and annulus disruption decreased over time. Finally, the incidence of cardiac arrest decreased significantly over time, suggesting that more expeditious management of complications and more rapid use of MCS to stabilize patients during these events might have played a role in improved outcomes (Fig. 2).
Figure 2Complication profile changes from year 2015 to 2019 for patients undergoing transcatheter aortic valve replacement procedure. The figure demonstrates that the incidence of high mortality complications, such as device embolization and annulus disruption, decreased remarkably over time, whereas other low mortality complications, such as coronary artery obstruction and ventricular failure, remained relatively stable.
The advancement in the safety of TAVR has resulted in progressively wider indications for patients undergoing valve replacement. However, perioperative complications still occur with significant mortality and morbidity.
Complications after transfemoral transcatheter aortic valve replacement with a balloon-expandable prosthesis: the importance of preventative measures and contingency planning.
In this large single-centre retrospective cohort study, we found the incidence of periprocedural catastrophic cardiac events was 2.5%, with an associated in-hospital mortality rate of 25.5%. Patients requiring emergency cardiac surgery experienced the worst outcomes, as the mortality rate was 54.5%. The most common cause of catastrophic cardiac events was cardiac perforation and tamponade, followed by acute ventricular failure, coronary-artery obstruction, aortic-root disruption, and device embolization. Echocardiography was an essential diagnostic tool during these events. Appropriate resuscitative measures, including the use of MCS, were crucial to stabilize these patients.
The incidence and associated mortality of catastrophic cardiac events in our study are comparable with or lower than previous study reports.
More importantly, the associated mortality rates decreased remarkably from 38.5% to 9.1% over the 5-year period, even though the incidence of catastrophic cardiac events was similar for those years. This suggests that rapid recognition and management of complications, once they occur, is critical in reducing mortality, in addition to efforts aimed at avoiding complications in the first place.
As experience plays an important role in reducing the complications, as well as optimizing management of the complications, we propose a standardized differential diagnosis and management algorithm for those rare events (Fig. 3). A limiting factor to this algorithm is that the patient's presentation could be complex, and the management sequence may not be exactly appropriate for the current proposal. However, this standardized approach can streamline the management process of the majority of cases, clarify options on how to proceed, and improve the patient's outcome. It is also important to point out that the proposed algorithm is based on the specific infrastructure at this institution. Therefore, in a different institutional environment, such an algorithm would have to be modified to reflect the specific availability of infrastructure.
Figure 3A proposed standardized algorithm for early differential diagnosis and perioperative management approaches of catastrophic cardiac events during transcatheter aortic valve replacement. This algorithm focuses on the expeditious use of diagnostic tools (echocardiography, angiography) and the application of mechanical circulatory support (MCS) in the temporization of patients with hemodynamic instability. AI, aortic insufficiency; CABG, coronary artery bypass graft, ECG, electrocardiogram; ICU, intensive care unit; PCI, percutaneous coronary intervention; PTCA, percutaneous transluminal coronary angioplasty.
Echocardiography as a guide to clinical decision making during refractory circulatory instability has been well established in both the cardiac and noncardiac surgical populations.
It is our experience that echocardiography is a critical diagnostic tool and provides a definitive diagnosis in many cases and guides subsequent resuscitative efforts. Studies have demonstrated that venoarterial ECMO could serve as a temporary bridge for life-threatening complications during TAVR procedure
At our institution, a closed-chest strategy is the preferred approach in the management of catastrophic cardiac events. Our data suggest that the majority of patients can be managed and stabilized with conservative measures. This is also related to the fact that most patients in our cohort were not deemed surgical candidates for open AVR because of their prohibitive surgical risk. This biased the heart team toward a closed-chest approach whenever possible. However, for patients with lower operative risks or other institutions with different interventional or surgical experiences, an open-chest approach to catastrophic cardiac events may be preferable and may further help to improve patient outcomes.
As the majority of patients undergoing TAVR are receiving sedation, it is important to consider the timing of intubation when catastrophic cardiac events occur. The decision to intubate a patient should be guided by the initial diagnosis of the etiology of collapse and the severity of hemodynamic instability. In patients with initial diagnoses that require surgical intervention (eg, device embolization), intubation should not be delayed. In contrast, if the hemodynamic deterioration is less severe, and management can be successfully performed without surgical intervention (eg, majority of cardiac tamponade), patients frequently do not require immediate intubation.
Our study found that the incidence of catastrophic events during TAVR using the CoreValve (Medtronic, Dublin, Ireland) was higher than Sapien (Edwards Lifesciences, Irvine, California) valve (6.5% vs 2.3%, P = 0.003). We reviewed the 3 patients who experienced catastrophic cardiac events during TAVR using the CoreValve. The etiology included cardiac tamponade, acute LV failure in a patient with pre-existing cardiogenic shock, and calcium emboli (not obstruction) to the LAD artery. These complications are not specifically associated with the CoreValve only. Their occurrence is most likely attributed to our limited experience with this type of valve.
Our study focused on early recognition, differential diagnosis, and management of catastrophic cardiac events. However, as the mortality rate with such events reached 25%, even in an experienced centre, efforts aimed at mitigating complications in the first place are essential to improve patient outcomes. All cases with major procedural adverse events should be discussed in a root-cause analysis conference. Any procedural steps that could have been improved upon or avoided should be discussed in detail, as well as case selection criteria.
Finally, it is important to differentiate between LV and RV perforation. The LV perforation primarily occurs secondary to the valve delivery wire inadvertently being pushed through the LV apex. It is suggested to use a “stiff” wire with a cushioned, soft spiral tip to reduce the risk of LV perforation.
The RV perforation primarily occurs secondary to the temporary pacing lead used for rapid ventricular pacing during valve deployment. Previously, it was identified that screw in pacing leads had higher perforation rates compared with passive temporary pacing wires.
In our institution, the majority of pacing wires currently used are the flexible balloon-tipped type. In addition, an active LV lead could also be inserted for rapid pacing and may mitigate risk of RV perforation.
Rapid pacing using the 0.035-in. retrograde left ventricular support wire in 208 cases of transcatheter aortic valve implantation and balloon aortic valvuloplasty.
Several factors are important limitations of our current study. First, our study only focused on severe forms of cardiac events that occurred intraoperatively and up to 2 hours postoperatively. Thus, we may have missed some of the milder presentations. This could have also led to an underestimation of the catastrophic events compared with the standard STS perioperative complication reporting system in which all complications occurring within 30 days of surgery are reported. Also, most of the catastrophic vascular complications are not included. Second, the usefulness of the proposed algorithm has not been officially validated in the current study. As such, we are uncertain whether improvements in mortality that we observed in our study can be solely attributed to our approach or merely happened concomitantly. Finally, the valves implanted in our study were mainly balloon-expandable Sapien valves, and the incidence of complications may not be generalizable to other types of valves. However, we believe the management strategy for catastrophic cardiac events will be similar regardless of the type of valve implanted.
Conclusions
Catastrophic cardiac events during TAVR are relatively rare but are associated with high rates of mortality. At our institution, we observed that mortality rates of these events decreased over time, which could be related to using a multidisciplinary team approach and a standardized treatment algorithm. We hope that understanding the incidence, outcomes, and management strategies for catastrophic events will be helpful for perioperative physicians and heart teams to manage these challenging situations.
Acknowledgements
We would like to thank Kelli Wallen, MPH, for her professional editing of this manuscript.
Funding Sources
Support was provided by institutional and departmental sources.
Disclosures
Dr Smalling is a consultant and proctor for Edwards LifeSciences. Dr Nguyen is a consultant for Edwards LifeSciences and LivaNova. The other authors have no conflicts of interest to disclose.
References
Reardon MJ
Van Mieghem NM
Popma JJ
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Surgical or transcatheter aortic-valve replacement in intermediate-risk patients.
Complications after transfemoral transcatheter aortic valve replacement with a balloon-expandable prosthesis: the importance of preventative measures and contingency planning.
Predictors and outcomes after transcatheter aortic valve implantation using different approaches according to the valve academic research consortium definitions.
Rapid pacing using the 0.035-in. retrograde left ventricular support wire in 208 cases of transcatheter aortic valve implantation and balloon aortic valvuloplasty.
Waiting lists for procedures are an accepted and even necessary part of the Canadian universal health care system, as in many other public health care jurisdictions, and have received significant public, government, and research attention. Provinces routinely monitor and publish waiting times for cardiac care, and individual programs strive to meet and even surpass wait-time benchmarks. Typically, death or upgrades on a waiting list occur early. Principles of wait-list management include the use of scoring systems for triage (which are useful but do not eliminate the risk of mortality) and specific measures for patients with symptomatic aortic-valve stenosis, who have a higher risk of death on a waiting list than those waiting for isolated coronary artery bypass graft (CABG) procedures.
Transcatheter aortic valve replacement (TAVR) has now become the predominant therapy for isolated, severe aortic stenosis.1 TAVR volume now exceeds all forms of surgical aortic valve replacement (SAVR) and can be performed with a 30-day mortality of 2.5%.1 Conversion to SAVR during TAVR occurs in only 0.4% of patients.1 Nevertheless, catastrophic complications can still occur during a TAVR. In this issue of the Canadian Journal of Cardiology, Liang et al. report the incidence, outcomes, and management of catastrophic cardiac events in patients undergoing TAVR from 2015 to 2019 at the University of Texas Health Science Center in Houston, Texas, and review their strategies for dealing with these complications.