Large Field-of-View Intravascular Ultrasound for Mitral and Tricuspid Valve-in-Valve Guidance: A Pilot Study.

Background: Actual expansion of a transcatheter heart valve (THV) might differ from nominal, particularly during nonaortic valve-in-valve for a degenerated bioprosthetic surgical heart valve (SHV). This pilot study compared THV expansion measured using large-field-of-view intravascular ultrasound (IVUS) vs. multi-slice computed tomography (MSCT) and assessed the correlation between THV dimensions and transvalvular gradients. Methods: Fourteen patients were successfully treated with mitral/tricuspid valve-in-valve SAPIEN 3 implantation sized using the true SHV inner diameter; all 14 had baseline MSCT and transvalvular gradients measured at baseline, postprocedure, and at discharge. Periprocedural IVUS (in 6 patients using a Philips 10MHz Vision PV035) was compared with postprocedural MSCT (in 9 patients) with offline measurements performed at 1-mm steps along the THV height. Overall, 190 MSCT and paired 124 IVUS cross-sections were analyzed. Results: There was very good agreement between IVUS THV dimensions and corresponding MSCT measurements (intraclass correlation coefficient ≥0.986 and p < 0.001). IVUS measured THV expansion (percent of the nominal cross-sectional area) was smaller within the inflow and middle of the THV overlapping the ring (85.9% ± 11.3%, 83.8% ± 11.8%) than within the outflow (98.8% ± 12.7%). The residual mean transvalvular gradient increased from periprocedural to predischarge (3.5 ± 2.0 vs. 6.3 ± 1.7 mmHg, p < 0.001). The only independent predictor of predischarge maximal transvalvular gradient was the smallest minimal inner THV frame diameter (r2 = 0.67), predicted by true SHV internal diameter (Beta = 0.066, 95% CI = 0.015-0.117, r2 = 0.49, p = 0.037). Conclusions: This pilot study is the first to report the feasibility of a large field-of-view IVUS for periprocedural measurement of actual THV expansion when deployed valve-in-valve. Minimal inner THV stent frame dimensions correlate with increased postprocedural transvalvular gradients.

Prognostic value of computed tomography derived measurements of pulmonary artery diameter for long-term outcomes after transcatheter aortic valve replacement.

BACKGROUND: An increase in pulmonary artery diameter (PAD) on multi-detector computed tomography (MDCT) may indicate pulmonary hypertension. We assessed the prognostic value of MDCT-derived measurements of PAD on outcomes after successful transcatheter aortic valve replacement (TAVR). METHODS: Consecutive patients treated with TAVR from February 2013 to October 2017, with a 68.8% rate of new generation valves, underwent pre-interventional MDCT with measurements of PAD (in the widest short-axis within 3 cm of the bifurcation) and ascending aortic diameter (AoD; at the level of the PAD). The PAD/AoD ratio was calculated. Patients with high-density lipoprotein cholesterol levels ≤46 mg/dl and C-reactive protein levels ≥0.20 mg/dl at baseline were identified as the frail group. One-year mortality was established for all subjects. RESULTS: Among studied 266 patients (median age, 82.0 years; 63.5% women) those who died at 1 year (n = 34; 12.8%) had larger PAD and PAD/AoD (28.9 [5.0] vs. 26.5 [4.6] mm and 0.81 [0.13] vs. 0.76 [0.13] mm vs. the rest of the studied subjects; P = 0.005 and P = 0.02, respectively) but similar AoD. The cutoff value for the PAD to predict 1-year mortality was 29.3 mm (sensitivity, 50%; specificity, 77%; area under the curve, 0.65). Patients with PAD >29.3 mm (n = 72; 27%) had higher 1-year mortality (23.6% vs. 8.8%, log-rank P = 0.001). Baseline characteristics associated with PAD29.3 mm were a bigger body mass index, more frequent diabetes mellitus, more prior stroke/transient ischemic attacks and atrial fibrillation, and lower baseline maximal aortic valve gradient with higher pulmonary artery systolic pressure (PASP). PAD >29.3 mm and frailty, but not baseline PASP, remained predictive of 1-year mortality in the multivariable model (hazard ratio [HR], 2.221; 95%CI, 1.038-4.753; P = 0.04 and HR, 2.801; 95% CI, 1.328-5.910; P = 0.007, respectively). CONCLUSION: PAD >29.3 mm on baseline MDCT is associated with higher 1-year mortality after TAVR, independently of echocardiographic measures of PH and frailty.