For Heart Failure, Novel Hemodynamic Index More Predictive Than Usual Metrics

A novel hemodynamic measurement, which divides a value derived from blood pressure (BP) by pulmonary capillary wedge pressure, better predicts clinical outcomes in patients with heart failure (HF) than traditional invasive hemodynamic metrics, suggested a study published in ESC Heart Failure.

The novel aortic pulsatility index (API) was previously derived from a retrospective cohort study of patients with HF and hemodynamic evidence of cardiogenic shock that required treatment with milrinone. API is calculated by subtracting the diastolic BP from the systolic BP, and dividing this value by the pulmonary capillary wedge pressure.

In this study of the API, researchers from the University of Chicago Medicine in Illinois evaluated individual-level data from the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial.

The investigators calculated routine hemodynamic measurements, such as the Fick cardiac index (CI), and the advanced hemodynamic metrics of API, cardiac power output (CPO), and pulmonary artery pulsatility index in 145 patients with HF.

All participants had complete, final hemodynamic data for assessment. The primary outcome was a composite 6-month endpoint of death or need for orthotopic heart transplant or left ventricular assist device.

Approximately 29% (n=45) of the patients experienced the primary composite outcome. A total of 68 patients had an API of 2.9 or more, while 77 patients had an API of less than 2.9. No difference was found when comparing the high vs low API groups in terms of baseline ejection fraction, end-diastolic diameter, or end-systolic diameter.

The primary API measurements significantly predicted the primary outcome in the multivariable analysis (odds ratio [OR], 0.59; 95% CI, 0.37-0.93; P =.02). In contrast, the primary outcome was not predicted by CI (OR, 1.06; 95% CI, 0.54-2.10; P =.86) or CPO (OR, 0.45; 95% CI, 0.08-2.42; P =.35) in the multivariable analysis.

Additionally, API best predicted the primary outcome in receiver operator characteristic analyses of final advanced hemodynamic measurements with a cutoff value of 2.9 (sensitivity, 76.2%; specificity, 55.3%; correctly classified, 61.4%; area-under-the-curve, 0.71) in comparison with CPO, CI, and pulmonary artery pulsatility index .

In Kaplan-Meier analyses, an API of 2.9 or more correlated with significantly greater freedom from the primary outcome vs an API of less than 2.9 (83.5% vs 58.4%, respectively; P =.001).

Limitations of the study included its retrospective nature as well as the inclusion of a data set that was 15 years old, which may not capture or reflect relatively recent HF management advancements.

The investigators emphasize the promise of the API, given the need for “additional clinical prognostic markers that could be used during this bellwether event” in a patient’s course.

Reference

Belkin MN, Alenghat FJ, Besser SA, et al. Aortic pulsatility index predicts clinical outcomes in heart failure: a sub-analysis of the ESCAPE trial. ESC Heart Fail. 2021;8(2):1522-1530. doi:10.1002/ehf2.13246