VE/VCO2 slope predicts RV dysfunction and mortality after left ventricular assist device: a fresh look at cardiopulmonary stress testing for prognostication.

Preoperative cardiopulmonary exercise testing (CPET) is well validated for prognostication before advanced surgical heart failure therapies, but its role in prognostication after LVAD surgery has never been studied. VE/VCO2 slope is an important component of CPET which has direct pathophysiologic links to right ventricular (RV) performance. We hypothesized that VE/VCO2 slope would prognosticate RV dysfunction after LVAD. All CPET studies from a single institution were collected between September 2009 and February 2019. Patients who ultimately underwent LVAD implantation were selectively analyzed. Peak VO2 and VE/VCO2 slope were measured for all patients. We evaluated their association with hemodynamic, echocardiographic and clinical markers of RV dysfunction as well mortality. Patients were stratified into those with a ventilatory class of III or greater. (VE/VCO2 slope of ≥ 36, n = 43) and those with a VE/VCO2 slope < 36 (n = 27). We compared the mortality between the 2 groups, as well as the hemodynamic, echocardiographic and clinical markers of RV dysfunction. 570 patients underwent CPET testing. 145 patients were ultimately referred to the advanced heart failure program and 70 patients later received LVAD implantation. Patients with VE/VCO2 slope of ≥ 36 had higher mortality (30.2% vs. 7.4%, p = 0.02) than patients with VE/VCO2 slope < 36 (n = 27). They also had a higher incidence of clinically important RVF (Acute severe 9.3% vs. 0%, Severe 32.6% vs 25.9%, p = 0.03). Patients with a VE/VCO2 slope ≥ 36 had a higher CVP than those with a lower VE/VCO2 slope (11.2 ± 6.1 vs. 6.0 ± 4.8 mmHg, p = 0.007), and were more likely to have a RA/PCWP ≥ 0.63 (65% vs. 19%, p = 0.008) and a PAPI ≤ 2 (57% vs. 13%, p = 0.008). In contrast, peak VO2 < 12 ml/kg/min was not associated with postoperative RV dysfunction or mortality. Elevated preoperative VE/VCO2 slope is a predictor of postoperative mortality, and is associated with postoperative clinical and hemodynamic markers of impaired RV performance.

Right Ventricular-Pulmonary Arterial Coupling in Patients With HF Secondary MR: Analysis From the COAPT Trial.

OBJECTIVES: The aim of this study was to determine the prognostic impact of right ventricular (RV)-pulmonary arterial (PA) coupling in patients with heart failure (HF) with severe secondary mitral regurgitation (SMR) enrolled in the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation) trial. BACKGROUND: RV contractile function and PA pressures influence outcomes in patients with SMR, but the impact of RV-PA coupling in patients randomized to transcatheter edge-to-edge repair (TEER) vs guideline-directed medical therapy (GDMT) is unknown. METHODS: RV-PA coupling was assessed by the ratio of RV free wall longitudinal strain derived from speckle-tracking echocardiography and noninvasively measured RV systolic pressure. Advanced RV-PA uncoupling was defined as RV free wall longitudinal strain/RV systolic pressure ≤0.5%/mm Hg. The primary endpoint was a composite of all-cause mortality or HF hospitalization at 24-month follow-up. RESULTS: A total of 372 patients underwent speckle-tracking echocardiography, and 70.2% had advanced RV-PA uncoupling. By multivariable analysis, advanced RV-PA uncoupling was strongly associated with an increased risk for the primary 24-month endpoint of death or HF hospitalization (HR: 1.87; 95% CI: 1.31-2.66; P = 0.0005). A similar association was present for all-cause mortality alone (HR: 2.57; 95% CI: 1.54-4.29; P = 0.0003). The impact of RV-PA uncoupling was consistent in patients randomized to TEER and GDMT alone. Compared with GDMT alone, the addition of TEER improved 2-year outcomes in patients with (48.0% vs 74.8%; HR: 0.51; 95% CI: 0.37-0.71) and those without (28.8% vs 47.8%; HR: 0.51; 95% CI: 0.27-0.97) advanced RV-PA uncoupling (Pinteraction = 0.98). CONCLUSIONS: In the COAPT trial, advanced RV dysfunction assessed by RV-PA uncoupling was a powerful predictor of 2-year adverse outcomes in patients with HF and SMR. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial]; NCT01626079).