Most Late Cardiac Mortality After TAVR Due to Heart Failure, Sudden Cardiac Death

Advanced heart failure and sudden cardiac death account for up to two-thirds of cardiac mortality in patients after TAVR, according to a study published in the February 10, 2015, issue of the Journal of the American College of Cardiology.Take Home: Most Late Cardiac Mortality After TAVR Due to Heart Failure, Sudden Cardiac Death

“Future studies should evaluate whether specific therapeutic strategies targeting [modifiable] factors, such as alternatives to the transapical approach in patients at risk of advanced [heart failure] not suitable for transfemoral access [or] further treatment of residual moderate or severe [aortic regurgitation] decrease these patients’ risk of cardiac death,” the authors say.

Josep Rodés-Cabau, MD, of Laval University (Quebec City, Canada), and colleagues retrospectively analyzed 3,726 TAVR patients (average age 81 years; 50.2% male) from 18 centers in North America, South America, and Europe. The mean logistic EuroSCORE was 19.4%, and one-quarter of patients had chronic obstructive pulmonary disease (COPD). Balloon- and self-expandable valves were used in 57% and 43% of patients, respectively, and TAVR was performed transfemorally in 79.7% and transapically in 16.3%. Moderate to severe aortic regurgitation was observed in 11.0% of patients postprocedure, and new-onset persistent left bundle branch block (LBBB) occurred in 13.3%. Mortality and stroke rates were 7.3% and 3.1%, respectively, at 30 days.

Predictors of Heart Failure

Over a mean follow-up of 22 months, 27.4% of patients died—17.8% of cardiovascular causes. Cumulative rates of 2-year overall and cardiac mortality were 26.6% and 9.6%, respectively. More specifically, advanced heart failure accounted for 15.2% of total deaths and 46.1% of cardiac deaths. Also, 5.6% of patients died of sudden cardiac death, which accounted 16.9% of cardiac deaths.

Multivariate analysis identified several predictors of death from advanced heart failure (table 1).

 Table 1. Predictors of Terminal Heart Failure After TAVR 

When death from other causes was included as a competing risk event, independent predictors of death from heart failure were paroxysmal/chronic A-fib, LVEF ≤ 40%, PASP > 60 mm Hg, transapical access, and moderate/severe aortic regurgitation after TAVR.

Additionally, among those with moderate or severe regurgitation post-TAVR (n = 374), one-third died within 2 years; 6.7% due to heart failure. Predictors of this outcome were lower mean gradient and PASP > 60 mm Hg, while the presence of moderate or severe regurgitation prior to TAVR was a protective factor.

Reduced-LVEF patients were not at increased risk of death from heart failure if they had moderate or severe prosthesis-patient mismatch.

Sudden Death Likely After LBBB

Predictors of sudden cardiac death were baseline LVEF ≤ 40% (HR 1.93; 95% CI 1.05-3.55) and new-onset persistent LBBB (HR 2.26; 95% CI 1.23-4.14). These remained when death from other causes was included as a competing risk event. When both risk factors were present in the same patient, the risk of sudden cardiac death increased to 12.3% at 1 year.

Given that 3.2% of patients with LBBB experienced sudden cardiac death at 2 years, the best QRS duration cut-off for determining this outcome was calculated to be > 160 milliseconds, with a sensitivity of 38.5% and a specificity of 87.8%. This cutoff was associated with a quadrupled risk of sudden death in this patient group (HR 4.78; 95% CI 1.56-14.63).

Baseline Comorbidities Increase Mortality Risk

According to the authors, while advanced heart failure and sudden cardiac death account for more than half of all deaths after surgical valve replacement, the percentage of both modes of death—in accordance with prior observations—was only about 20% in their study. “This may be attributable to the high prevalence of severe noncardiac comorbidities in this population, leading to a high incidence of death from noncardiac causes,” they say.

In a telephone interview with TCTMD, Dr. Rodés-Cabau said the findings were “more or less expected” as baseline comorbidities have already been shown to cause poor outcomes after TAVR. Additionally, he said, that transapical access, “which is associated with a greater degree of myocardial injury, was associated with a higher rate of heart failure leading to death was maybe more unexpected but makes sense.”

Michael J. Mack, MD, of Baylor Health Care System (Dallas, TX), agreed but added that a transapical approach “is usually a surrogate for sicker patients with more comorbidities.” He told TCTMD in a telephone interview that “the paper is worthwhile in that it does reinforce what we sort of already know, but despite the fact that we all know it, these factors haven't gone away and still play a role.”

Yet the effect of LBBB on mortality after TAVR remains “highly controversial in both surgical and transcatheter fields,” the authors write. They suggest the importance of measuring QRS duration in these patients, noting, “The implantation of a preventive pacemaker before hospital discharge may be justified while awaiting results of further studies.”

They call for randomized trials to “define optimum management strategies for patients with modifiable risk factors for development of [heart failure] or cardiac death following TAVR.”

A Call for Granularity

In an accompanying editorial, Thierry Lefèvre, MD, of the Institut Cardiovasculaire Paris Sud (Massy, France), suggests 3 strategies for improving TAVR outcomes:

  • Enhancing patient screening, equipment, and implantation techniques
  • Looking for risk markers for cardiac death from heart failure and reducing modifiable risk factors such as transapical access and postprocedural regurgitation
  • Reducing the risk of sudden cardiac death by identifying QRS duration and other methods of controlling LBBB, which may be clarified by the MARE study

Additionally, Dr. Mack suggested the need for examining individual cases. “Once you begin to get [30-day] mortality down into the single-digit range, the only way to really move the needle much farther is to look at every single patient and figure out what the issue was in that patient. You have to get that granular to be able to get from 5% to 3% to 1%,” he said.

For example, Dr. Mack noted, in an oxygen-dependent patient with very severe COPD, “you probably should spend a lot of time sorting through whether any of that oxygen-dependence is due to heart failure… and if fixing the aortic valve is going to make a difference.” Also, he added, choosing the right valve for each patient will lead to better outcomes, especially in those with LBBB.

Note: Coauthor Alexandre Abizaid, MD, is a faculty member of the Cardiovascular Research Foundation, which owns and operates TCTMD.


Sources:

1. Urena M, Webb JG, Eltchaninoff H, et al. Late cardiac death in patients undergoing transcatheter aortic valve replacement: incidence and predictors of advanced heart failure and sudden cardiac death. J Am Coll Cardiol. 2015;65:437-448.

2. Lefèvre T. Cardiac death after TAVR: moving up a notch [editorial]. J Am Coll Cardiol. 2015:65:449-451.

Disclosures:

 

  • Dr. Rodés-Cabau reports serving as a consultant for Edwards Lifesciences and St. Jude Medical and receiving a research grant from Edwards Lifesciences.
  • Dr. Lefèvre reports serving as a proctor for Edwards Lifesciences and receiving minor fees from Direct Flow Medical, Medtronic, and Symetis.
  • Dr. Mack reports serving on the executive committee of the PARTNER trial and steering committee of TVT Registry of the United States.

 

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