Abstract 11969: Endocardial Viability Ratio is Associated With Survival in Advanced Heart Failure Patients

Abstract

Introduction: Myocardial oxygen supply is an important determinant of cardiac function. The Endocardial Viability Ratio (EVR), a measure of myocardial oxygen supply-demand balance, is calculated as a ratio of the diastolic pressure time index [(diastolic blood pressure - left ventricular end diastolic pressure) x (60 sec/heart rate - 0.2 sec)] and tension time index [systolic pressure x 0.2 sec]. We hypothesized that low EVR would be associated with adverse events in patients with heart failure (HF). Methods: EVR was calculated in the invasive arm of the ESCAPE trial in patients with available discharge blood pressure, pulmonary arterial wedge pressure, and heart rate as the ratio of the diastolic pressure time index (a measure of coronary blood supply) and tension time index (a measure of myocardial oxygen demand). Kaplan-Meier analysis and Cox proportional hazards regression was used to assess associations with EVR and a composite death endpoint including cardiac transplantation and left ventricular assist device implantation. Results: Among 143 patients (56.9 ± 13.3 years, 30.1% female), the median EVR was 1.168 (IQR 0.923-1.398). Survival during 180 days of follow-up was worse in patients with EVR below the median (p=0.0004) (Figure panel 1A). Among the 10 patients with EVR < 0.7, considered to represent subendocardial ischemia, 50% reached this endpoint within 100 days (p=0.01 versus remaining patients) (Figure 1B). An increase of 0.1 in EVR was associated with an 18% relative risk reduction for this endpoint (HR 0.82, 95% CI 0.74-0.91, p=0.0002), while an increase of 0.5 in EVR was associated with a 62% relative risk reduction (HR 0.38, 95% CI 0.22-0.64, p=0.002). Conclusion: Decreased EVR, a marker of myocardial oxygen supply, is associated with adverse events in advanced HF patients. Further studies on the prognostic utility of EVR in HF are needed.