A new study has identified the occurrence of periprocedural myocardial injury (PPMI) in approximately 14% of patients undergoing transcatheter aortic valve replacement (TAVR), which negatively impacts early and late survival rates.
Findings by the research team reveal that in addition to baseline patient characteristics such as female sex and peripheral artery disease, the use of balloon pre- and postdilation during TAVR tends to increase the risk of PPMI.
“Because predilation and postdilation tended to be associated with PPMI in our cohort,” the study pointed out, “and considering the higher incidence of these maneuvers in procedures involving self-expandable valve (SEV) systems, our results suggest that the higher PPMI rate in patients receiving a SEV might actually be related to these maneuvers, rather than to the valve type itself. The postulated mechanism of this injury could be the calcified particles that embolize to the coronary arteries during balloon dilations.”
Impact on cardiac troponin release
Led by Carlos Real, MD, from Laval University in Quebec City, and Hospital Clínico San Carlos in Madrid, the team also suggested that any additional intervention during the procedure may have an impact on cardiac troponin release.
Published Monday online and in the May 22 issue of JACC: Cardiovascular Interventions, the study sought to determine the incidence, predictors, and clinical impact of PPMI following TAVR as recently defined by the Valve Academic Research Consortium (VARC)-3.
VARC-3’s consensus document increases the troponin threshold for defining PPMI to 70 times the local laboratory upper reference limit (URL). However, this definition for PPMI post-TAVR has not yet been clinically validated.
The study included 1,394 consecutive patients who underwent a transarterial TAVR procedure with a newer-generation transcatheter valve from 2015 to 2022, during which the high-sensitivity troponin assay became available in the two centers contributing patients to this study.
The mean age of the population was 79.5±7.5 years, with 46.4% women and a mean European System for Cardiac Operative Risk Evaluation (EuroSCORE) II of 5.46% ± 6.13%.
High-sensitivity troponin levels were assessed at baseline and within 24 hours after the procedure, with PPMI defined according to VARC-3 criteria (vs. ≥15 times the URL according to the VARC-2 definition). Baseline, procedural and follow-up data were prospectively collected.
Independent predictors of PPMI
Findings revealed that PPMI was diagnosed in 193 (14.0%) patients, with female sex and peripheral artery disease noted as independent predictors of PPMI (P<0.01 for both).
Additional results revealed that PPMI was associated with a higher risk of mortality at 30-day follow-up (hazard ratio [HR]: 2.69, 95% confidence interval [CI]: 1.50-4.82; P=0.001).
The researchers also calculated the risk of all-cause mortality for one year (HR: 1.54; 95% CI: 1.04-2.27; P =0.032; and for cardiovascular mortality (HR: 3.04; 95% CI: 1.68-5.50; P<0.001) follow-up.
The Canada- and Italy-based team also found PPMI according to VARC-2 criteria had no impact on mortality.
“The incidence of VARC-3–defined PPMI was 4 times lower than PPMI defined according to prior criteria,” the authors wrote.
“A low troponin elevation threshold leads to an increase in sensitivity with a potential overestimation of the PPMI incidence, negatively affecting the results of the tested therapy,” they added.
Mechanical myocardial stretching
Commenting on the predictors of PPMI, the team said that additional rapid pacing was needed for each dilation, which has also been associated with PPMI, likely secondary to hypotension-induced ischemia during the rapid pacing episodes.
They added that mechanical myocardial stretching during consecutive dilations would also promote cardiac troponin release.
“All these findings suggest that PPMI is an indicator of procedural complexity, with these patients being more susceptible to periprocedural complications,” the authors wrote. “In our study, post-TAVR in-hospital events such as myocardial infarction, stroke, and pacemaker implantation, as well as moderate-to-severe paravalvular leak, were higher in the PPMI group, which supports the previously stated hypothesis. Thus, this suggests that patients with post-TAVR PPMI could benefit from a closer clinical follow-up for preventing short-term and midterm adverse events.”
Validation of VARC-3 PPMI criteria
An accompanying editorial comment says the study validates the VARC-3 criteria, pointing out that PPMI is quite similar to what has been reported after percutaneous coronary intervention with a consistent definition of PPMI.
The editorialists, Paul Guedeney, MD, Gabriel Chevrot, MD, and Jean-Philippe Collet, MD, PhD, all from Sorbonne Université in Paris, commend the study’s validation of the VARC-3 PPMI criteria with the use of a high-sensitivity cardiac troponin threshold.
“PPMI is rarer with this updated definition but more impactful in terms of prognosis,” the expert commenters wrote. “Much more remains to be done to better assess if PPMI is a marker of risk or a risk factor with potential preventable upstream actions.”
They also point out that in the study, both pre- and postdilatation were associated with a higher risk of VARC-3 PPMI, albeit not reaching statistical significance with P values of 0.053 and 0.059, respectively, warranting further investigation.
Real C, Avvedimento M, Nuche J, et al. Myocardial Injury After Transcatheter Aortic Valve Replacement According to VARC-3 Criteria. JACC Cardiovasc Interv. 2023;16:1221–1232.
Guedeney P, Chevrot G, Collet J-P. VARC-3 Criteria: Adding Prognosis to Injury. JACC Cardiovasc Interv. 2023;16:1233–1235.
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