Transcatheter aortic valve implantation without prior balloon valvuloplasty is associated with less pronounced markers of myocardial injury.

BACKGROUND: Aortic valve stenosis is the most common valvulopathy in developed countries. Transcatheter aortic valve implantation (TAVI) is a therapeutic alternative in symptomatic patients at high or prohibitive perioperative risk. Predilatation by balloon aortic valvuloplasty (BAV) under rapid ventricular pacing (RVP) has been a routine part of TAVI. However, both RVP and BAV carry substantial risks and an increasing number of interventional centers are performing TAVI without predilatation (direct TAVI). A transient decrease of left ventricular function and elevated markers of myocardial injury after TAVI with predilatation were observed in previous studies. In this study, we investigated whether direct TAVI was associated with a similar increase in cardiac biomarkers and decrease in ejection fraction in a cohort of our patients.

METHODS: Consecutive patients undergoing TAVI without predilatation using a self-expanding system at a single-center between April 2013 and December 2015 were followed up for one year and were retrospectively analyzed regarding mortality, safety and efficacy endpoints as well as common laboratory and echocardiographic parameters.

RESULTS: A total of 164 patients (83±6 years; 56% female) were included in the analysis. According to the Valve Academic Research Consortium 2 (VARC-2) criteria the technical success rate was 96.3% and 89.1% of patients remained free of a combined safety endpoint at 30 days. Mortality rates at 30 days and 1 year were 3.0% (n= 5) and 10.4% (n= 17), respectively. TAVI without predilatation was highly effective in lowering aortic valve peak velocity from 4.4 ±0.6 m/s before to 1.7 ±0.5 m/s (p <0.01), and mean pressure gradient across the valve from 48.7 ±15.1 mmHg to 8.3±4.5 mmHg (<0.05). Left ventricular function remained unaltered after the intervention (51±10% prior to TAVI and 51±9% post TAVI), whereas high sensitive troponin T (hs-TnT), a well-established marker for myocardial injury, increased significantly from 26 ng/L (interquartile range = 18.00-44.00) to 119 ng/L (interquartile range = 73.25-166.00, p <0.001) during this time. Notably, an increase in the plasma levels of hs-TnT >15 times the upper limit of normal was associated with mortality both one month and one year after TAVI.

CONCLUSIONS: TAVI without predilatation is feasible, safe and effective for aortic valve replacement in symptomatic patients with severe aortic stenosis who are at high perioperative risk. In contrast to a cohort of patients who underwent TAVI with predilatation previously published by another center, our patients did not suffer from transient impairment of left ventricular function. As a marker of myocardial injury, hs-TnT showed a less pronounced increase than reported previously. This might be a marker for a prognostic benefit as hs-TnT has been shown to be a strong predictor of outcome in patients undergoing TAVI. We conclude that direct TAVI is a less invasive option involving less myocardial stress.