Baseline PA/BSA ratio in patients undergoing transcatheter aortic valve replacement - A novel CT-based marker for the prediction of pulmonary hypertension and outcome.

BACKGROUND: Pulmonary hypertension (pH) has a prognostic impact on patients undergoing transcatheter aortic valve replacement (TAVR). Pulmonary artery (PA) dilatation assessed by multidetector computed tomography (MDCT) has the potential to predict PH. The aim of the study was to evaluate the clinical parameters associated with PA dilatation and to investigate its prognostic relevance in patients undergoing TAVR. METHODS: In 770 patients undergoing TAVR between February 2016 and July 2019, PA diameter was measured by MDCT before TAVR. Additionally, PA diameter divided by ascending aorta diameter or body surface area (BSA) was calculated. RESULTS: Of all the CT-derived parameters compared with a receiver operating characteristic curve, the value for PA/BSA with a median of 1.68 (IQR 1.47, 1.91) cm/m2 showed the greatest area-under-the-curve (0.75) for predicting PH at baseline. Based on this median, patients were assigned to a small PA/BSA (n = 386) or a large PA/BSA (n = 384) group. Hereby, a large PA/BSA was independently associated with PH at baseline (OR:8.39 [5.36-13.14], p < 0.001) and after TAVR (OR:1.73 [1.18-2.53], p = 0.005). A large PA/BSA was associated with a significantly higher cumulative two-year all-cause mortality compared to small PA/BSA (30.0% vs. 13.7%, p < 0.001), which was supported in the multivariable model (HR:1.87; 95%CI, 1.12-3.04; p = 0.017). CONCLUSION: Patients with a large PA/BSA on MDCT are more likely to have PH at baseline and after TAVR. Large PA/BSA is associated with an increased risk of mortality and could provide additional information for risk stratification in patients undergoing TAVR.

Spleen Size and Thrombocytopenia After Transcatheter Aortic Valve Implantation.

The pathophysiology of thrombocytopenia after transcatheter aortic valve implantation (TAVI) thrombocytopenia is still poorly understood. We assessed the association of spleen size with acquired thrombocytopenia in patients undergoing TAVI. We included 732 patients who underwent TAVI with new generation transcatheter heart valves (THVs) at our center from February 2016 to July 2019. We measured splenic volume index in consecutive patients derived from multidetector row computed tomographic datasets. Patients were stratified according to post-TAVI thrombocytopenia, which was defined as a decline in platelet count (DPC) ≥50% at nadir, and evaluated regarding baseline characteristics and outcome parameters. After the procedure, platelet counts declined from 212.9 ± 67.4 × 109/L at baseline to 138.8 ± 49.8 × 109/L at nadir after a median of 2 days (interquartile range [IQR] 2 to 3). Of all patients, 10.1% showed a DPC ≥50%. Compared with patients with DPC <50%, patients with DPC ≥50% had significantly lower splenic volume index (95.5 ml/m2 [IQR 78.0 to 123.7] vs 85.8 ml/m2 [IQR 71.4 to 102.6], p = 0.008). A multivariable analysis revealed that the splenic volume index was negatively associated with a DPC ≥50% (OR 0.89, 95% CI 0.82 to 0.97, p = 0.005), independent of the type of THV (balloon-expandable THV: OR 2.06, 95% CI 1.13 to 3.76, p = 0.02), major bleeding (OR 13.40, 95% CI 3.58 to 50.40, p <0.001), blood transfusion (OR 3.63, 95% CI 1.54 to 8.56, p = 0.003), or postprocedural paravalvular leakage ≥moderate (OR 5.48, 95% CI 1.23 to 24.40, p = 0.03). Furthermore, DPC ≥50% was independently associated with 1-year mortality (HR 3.36, 95% CI 1.66 to 6.81, p <0.001). In conclusion, acquired thrombocytopenia remains prevalent in modern TAVI patients. Spleen size appears to be associated with the occurrence of thrombocytopenia after TAVI, which is independently correlated with 1-year mortality.