Left ventricular fibrosis as a main determinant of filling pressures and left atrial function in advanced heart failure

Aims: Advanced heart failure (AdHF) is characterized by variable degrees of left ventricular (LV) dysfunction, myocardial fibrosis, and raised filling pressures which lead to left atrial (LA) dilatation and cavity dysfunction. This study investigated the relationship between LA peak atrial longitudinal strain (PALS), assessed by speckle-tracking echocardiography (STE), and invasive measures of LV filling pressures and fibrosis in a group of AdHF patients undergoing heart transplantation (HTX).

Methods and results: We consecutively enrolled patients with AdHF who underwent HTX at our Department. Demographic and basic echocardiographic data were registered, then invasive intracardiac pressures were obtained from right heart catheterization, and STE was also performed. After HTX, biopsy specimens from explanted hearts were collected to quantify the degree of LV myocardial fibrosis. Sixty-four patients were included in the study (mean age 62.5 ± 11 years, 42% female). The mean LV ejection fraction (LVEF) was 26.7 ± 6.1%, global PALS was 9.65 ± 4.5%, and mean pulmonary capillary wedge pressure (PCWP) was 18.8 ± 4.8 mmHg. Seventy-three % of patients proved to have severe LV fibrosis. Global PALS was inversely correlated with PCWP (R = -0.83; P < 0.0001) and with LV fibrosis severity (R = -0.78; P < 0.0001) but did not correlate with LVEF (R = 0.15; P = 0.2). Among echocardiographic indices of LV filling pressures, global PALS proved the strongest [area under the curve 0.955 (95% confidence interval 0.87-0.99)] predictor of raised (>18 mmHg) PCWP.

Conclusion: In patients with AdHF, reduced global PALS strongly correlated with the invasively assessed LV filling pressure and degree of LV fibrosis. Such relationship could be used as non-invasive indicator for optimum patient stratification for therapeutic strategies.