Pulmonary Hypertension in Aortic and Mitral Valve Disease

Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist (TOPCAT) patients with heart failure and preserved left ventricular ejection fraction assigned to spironolactone did not achieve a significant reduction in the primary composite outcome (time to cardiovascular death, aborted cardiac arrest, or hospitalization for management of heart failure) compared with patients receiving placebo. In a post hoc analysis, an ≈4-fold difference was identified in this composite event rate between the 1678 patients randomized from Russia and Georgia compared with the 1767 enrolled from the United States, Canada, Brazil, and Argentina (the Americas).

This study sought to define the prevalence, severity, and significance of pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) in the general community. Although HFpEF is known to cause PH, its development is highly variable. Community-based data are lacking, and the relative contribution of pulmonary venous versus pulmonary arterial hypertension (HTN) to PH in HFpEF is unknown. We hypothesized that PH would be a marker of symptomatic pulmonary congestion, distinguishing HFpEF from pre-clinical hypertensive heart disease. This community-based study of 244 HFpEF patients (age 76 +/- 13 years; 45% male) was followed up using Doppler echocardiography over 3 years. Control subjects were 719 adults with HTN without HF (age 66 +/- 10 years; 44% male). Pulmonary artery systolic pressure (PASP) was derived from the tricuspid regurgitation velocity and PH defined as PASP >35 mm Hg. Pulmonary capillary wedge pressure (PCWP) was estimated from the ratio of early transmitral flow velocity to early mitral annular diastolic velocity. In HFpEF, PH was present in 83% and the median (25th, 75th percentile) PASP was 48 (37, 56) mm Hg. PASP increased with PCWP (r = 0.21; p < 0.007). Adjusting for PCWP, PASP was higher in HFpEF than HTN (p < 0.001). The PASP distinguished HFpEF from HTN with an area under the receiver-operating characteristic curve of 0.91 (p < 0.001) and strongly predicted mortality in HFpEF (hazard ratio: 1.3 per 10 mm Hg; p < 0.001). PH is highly prevalent and often severe in HFpEF. Although pulmonary venous HTN contributes to PH, it does not fully account for the severity of PH in HFpEF, suggesting that a component of pulmonary arterial HTN also contributes. The potent effect of PASP on mortality lends support for therapies aimed at pulmonary arterial HTN in HFpEF.

Approximately half of all patients with heart failure have preserved ejection fraction (HFpEF) and, as life expectancies continue to increase in western societies, the prevalence of HFpEF will continue to grow. In contrast to heart failure with reduced ejection fraction (HFrEF), no treatment has been proven in pivotal clinical trials to be effective for HFpEF, largely because of the pathophysiological heterogeneity that exists within the broad spectrum of HFpEF. This syndrome was historically considered to be caused exclusively by left ventricular diastolic dysfunction, but research has identified several other contributory factors, including limitations in left ventricular systolic reserve, systemic and pulmonary vascular function, nitric oxide bioavailability, chronotropic reserve, right heart function, autonomic tone, left atrial function, and peripheral impairments. Multiple individual mechanisms frequently coexist within the same patient to cause symptomatic heart failure, but between patients with HFpEF the extent to which each component is operative can differ widely, confounding treatment approaches. This Review focuses on our current understanding of the pathophysiological mechanisms underlying HFpEF, and how they might be mechanistically related to typical risk factors for HFpEF, including ageing, obesity, and hypertension.