Usefulness of noninvasive estimate of pulmonary vascular resistance to predict mortality, heart failure, and adverse cardiovascular events in Patients With stable coronary artery disease (from the Heart and Soul Study)

Abstract

Pulmonary vascular resistance (PVR) is an important hemodynamic variable that affects prognosis and therapy in a wide range of cardiovascular and pulmonary conditions. We sought to determine whether a noninvasive estimate of PVR predicts adverse outcomes in patients with stable coronary artery disease. Using Doppler echocardiography we measured the estimated PVR (defined as the ratio of the tricuspid regurgitant velocity [TRV] to the velocity-time integral [VTI] of the right ventricular outflow tract [RVOT]) in 795 ambulatory patients with stable coronary artery disease. Participants were categorized by quartiles of the TRV/VTI RVOT ratio. Hazard ratios (HRs) and 95% confidence intervals were calculated for all-cause mortality, heart failure hospitalization, and adverse cardiovascular events (cardiovascular death, nonfatal myocardial infarction, or stroke). After 4.3 years of follow-up there were 161 deaths, 44 deaths from cardiovascular causes, 103 heart failure hospitalizations, and 120 adverse cardiovascular events. Compared with patients in the lowest TRV/VTI RVOT quartile, those in the highest quartile were at increased risk of all-cause mortality (unadjusted HR 1.8, 95% confidence interval 1.3 to 2.5), heart failure hospitalization (unadjusted HR 2.9, 95% confidence interval 2.0 to 4.3), and adverse cardiovascular events (unadjusted HR 2.0, 95% confidence interval 1.4 to 2.9). After multivariate adjustment, patients in the highest quartile were at increased risk of heart failure hospitalizations (adjusted HR 2.5, 95% confidence interval 1.3 to 4.7). In conclusion, a noninvasive estimate of PVR (TRV/VTI RVOT ratio) predicts mortality, heart failure hospitalization, and adverse cardiovascular events in patients with stable coronary artery disease.

Figures

Figure 1

Noninvasive estimation of PVR by TRV/VTIRVOT (TRV 2.4 m/s, VTIRVOT 0.21 m, TRV/VTIRVOT 2.4 m/s ÷ 0.21 m = 11 s−1). CW = continuous wave doppler; HR = heart rate; Min Grad = minimum gradient; Pk Grad = peak gradient; PV Vmax = maximum velocity.

Figure 2

Outcome by quartiles I, II, III, and IV of TRV/VTIRVOT (x axis) with annual event rates for adverse cardiovascular events (y axis).