Impact of Left Ventricular Outflow Tract Calcium on Transcatheter Aortic Valve Replacement Outcomes

Raina, Anvi

Background:
Significant left ventricular outflow tract (LVOT) calcium has originally been associated with increased paravalvular regurgitation (PVL), aortic root injury, and decreased survival in patients undergoing transcatheter aortic valve replacement (TAVR). However, real-life impact of LVOT calcium with newer generation of TAVR valves is unknown.

Methods:
Patients who underwent TAVR for severe aortic valve stenosis between January 2016 to March 2018 at a single academic center were analyzed. Patients with bicuspid aortic valve and valve-in-valve TAVR were excluded. Pre-operative CT angiography and pre-discharge transthoracic echocardiogram (TTE) were analyzed. The presence of LVOT calcium within 6 mm of the annulus was assessed and characterized by dimensions, area, and volume using 3-mensio Structural Heart™ software. The primary endpoint was presence of ≥ mild PVL at discharge. Secondary endpoints included need for new pacemaker, transvalvular mean gradient at discharge, need for post-dilation, new pericardial effusion and 30-day mortality.

Results:
A total of 269 patients were included, of which 75 had LVOT calcification (calcium group). The non-calcium group was younger (80±8 vs 82±7 years; p=0.02), had more patients with diabetes (81.7% vs 18.3%; p=0.004), and higher rate of prior pacemaker (87.2% vs 12.8%; p=0.02) compared to the calcium group. The two groups had no difference in the need for post-dilation, residual gradient, new pacemaker, acute kidney injury, new pericardial effusion and 30-day mortality. Predictors of ≥ mild PVL were use of a self-expandable valve (OR = 2.09, 95% CI: 0.07-0.23, p=0.037) and post-dilation (OR = 4.25, 95% CI: 0.22-0.60, p<0.001). Severity of LVOT calcium, LVOT calcium volume, and degree of oversizing were not found to be predictors of ≥ mild PVL at discharge in this cohort.

Conclusions:
The presence of LVOT calcium does not negatively impact outcomes during TAVR in real-life experience with new generations of valves. These results need to be validated in larger cohorts.