Diagnostic performance of pressure-bounded coronary flow reserve.

Fluid dynamics studies have proposed that coronary flow reserve can be calculated from coronary artery pressure instead of coronary blood flow. We sought to investigate the diagnostic performance of pressure-bounded coronary flow reserve (pb-CFR) compared with CFR measured by conventional thermodilution method (CFRthermo) in the clinical setting. Pressure guidewire was used to measure CFRthermo and fractional flow reserve (FFR) in left anterior descending coronary artery in 62 patients with stable coronary artery disease. Pb-CFR was calculated only with resting distal coronary artery pressure (Pd), resting aortic pressure (Pa) and FFR. Pb-CFR was moderately correlated with CFRthermo (r = 0.54, P < 0.001). Pb-CFR showed a poor agreement with CFRthermo, presenting large values of mean difference and root mean square deviation (1.5 ± 1.4). Pb-CFR < 2.0 predicted CFRthermo < 2.0 with an accuracy of 79%, sensitivity of 83%, specificity of 78%, positive predictive value of 48%, negative predictive value of 95%. The discordance presenting CFRthermo < 2.0 and pb-CFR ≥ 2.0 was associated with diffuse disease (P < 0.001). The discordance presenting CFRthermo ≥ 2 and pb-CFR < 2 was associated with a high FFR (P = 0.002). Pb-CFR showed moderate correlation and poor agreement with CFRthermo. Pb-CFR might be reliable in excluding epicardial coronary artery disease and microcirculatory disorders.

Midterm Outcomes of Underweight Patients Undergoing Transcatheter Aortic Valve Implantation: Insight From the LAPLACE-TAVR Registry.

Background: Obesity is a major risk factor for cardiovascular disease; however, a paradoxical effect of obesity has been reported in patients with heart failure or myocardial infarction. Although several studies have suggested the same obesity paradox in patients undergoing transcatheter aortic valve replacement (TAVR), they included a limited number of underweight patients. Objectives: This study aimed to clarify the effect of being underweight on TAVR outcomes. Methods: We retrospectively analyzed 1,693 consecutive patients undergoing TAVR between 2010 and 2020. The patients were categorized according to body mass index: underweight (<18.5 kg/m2; n = 242), normal weight (18.5 to 25 kg/m2; n = 1,055), and overweight (>25 kg/m2; n = 396). We compared midterm outcomes after TAVR among the 3 groups; all clinical events were in accordance with the Valve Academic Research Consortium-2 criteria. Results: Underweight patients were more likely to be women and have severe heart failure symptoms, peripheral artery disease, anemia, hypoalbuminemia, and pulmonary dysfunction. They also had lower ejection fractions, smaller aortic valve areas, and higher surgical risk scores. Device failure, life-threatening bleeding, major vascular complications, and 30-day mortality occurred more frequently in underweight patients. The midterm survival rate of the underweight group was inferior to those of the other 2 groups (P < 0.0001; average follow-up, 717 days). In the multivariate analysis, underweight was associated with noncardiovascular mortality (HR: 1.78; 95% CI: 1.16-2.75) but not cardiovascular mortality (HR: 1.28; 95% CI: 0.58-1.88) after TAVR. Conclusions: Underweight patients had a worse midterm prognosis, demonstrating the obesity paradox in this TAVR population. (Outcomes of transcatheter aortic valve implantation in Japanese patients with aortic stenosis: multi-center registry; UMIN000031133).