Ventricular longitudinal function by cardiovascular magnetic resonance predicts cardiovascular morbidity in HFrEF patients

Abstract

Aims: Ventricular longitudinal function measured as basal-apical atrioventricular plane displacement (AVPD) or global longitudinal strain (GLS) is a potent predictor of mortality and could potentially be a predictor of heart failure-associated morbidity. We hypothesized that low AVPD and GLS are associated with the combined endpoint of cardiovascular mortality and heart failure-associated morbidity.

Methods and results: Two hundred eighty-seven patients (age 62 ± 12 years, 78% male) with heart failure with reduced (≤40%) ejection fraction (HFrEF) referred to a cardiovascular magnetic resonance exam were included. Ventricular longitudinal function, ventricular volume, and myocardial fibrosis or infarction were analysed from cine and late gadolinium enhancement images. National registries provided data on causes of cardiovascular hospitalizations and cardiovascular mortality for the combined endpoint. Time-to-event analysis capable of including reoccurring events was employed with a 5-year follow-up. HFrEF patients had EF 26.5 ± 8.0%, AVPD 7.8 ± 2.4 mm, and GLS -7.5 ± 3.0%. In contrast, ventricular longitudinal function was approximately twice as large in an age-matched control group (AVPD 15.3 ± 1.6 mm; GLS -20.6 ± 2.0%; P < 0.001 for both). There were 578 events in total, and the majority were HF hospitalizations (n = 418). Other major events were revascularizations (n = 64), cardiovascular deaths (n = 40), and myocardial infarctions (n = 21). One hundred fifty-five (54%) patients experienced at least one event (mean 2.0, range 0-64). Of these patients, 119 (71%) had three events or fewer, and the first three events comprised 51% of all events (295 events). Patients in the bottom AVPD or GLS tertile (<6.8 mm or >-6.1%) overall experienced more than 3 times as many events as the top tertile (>8.8 mm or <-8.4%; P < 0.001). Patients in this tertile also faced more cardiovascular deaths (P < 0.05), HF hospitalizations (P = 0.001), myocardial infarctions (only GLS: P = 0.032), and accumulated longer in-hospital length-of-stay overall (AVPD 20.9 vs. 9.1 days; GLS 22.4 vs. 6.5 days; P = 0.001 for both), and from HF hospitalizations (AVPD 19.3 vs. 8.3 days; GLS 19.3 vs. 5.4 days; P = 0.001 for both). In multivariate analysis adjusted for significant covariates, AVPD and GLS remained independent predictors of events (hazard ratio 1.12 per-mm-decrease and 1.13 per-%-increase) alongside hyponatremia (<135 mmol/L), aetiology of HF, and LV end-diastolic volume index.

Conclusions: Low ventricular longitudinal function is associated with an increase in number of events as well as longer in-hospital stay from cardiovascular causes. In addition, AVPD and GLS have independent prognostic value for cardiovascular mortality and morbidity in HFrEF patients.

Keywords: Contractile function; Heart failure; Magnetic resonance imaging; Mortality/survival.

Figure 1

Plot showing moderate to good (r = 0.65–66) correlations between ventricular longitudinal function measurements [atrioventricular plane displacement (AVPD), global longitudinal strain (GLS)] and ejection fraction (EF). The correlation between AVPD and GLS was stronger at r = −0.76.

Figure 2

Cumulative event plot according to Kaplan–Meier of AVPD (A) and GLS (B) tertiles, generated from only the first event. There was a higher probability of experiencing an event for patients in tertiles with the lowest ventricular longitudinal function (AVPD, P = 0.01; GLS, P < 0.0001). The number of patients in each tertile still remaining in the study for each year is shown as ‘Number at risk’.

Figure 3

Mean cumulative function (MCF) of events by tertiles of (A) atrioventricular plane displacement (AVPD) and (B) global longitudinal strain (GLS). The horizontal axes show the time since the study entry and the vertical axes show the average number of events an individual had experienced during follow‐up. Each colour displays the MCF and predicted confidence intervals for each tertile. On average, a patient in the lowest tertile of ventricular longitudinal function (red) had over 3 times as many events during follow up compared with the highest tertile (blue). *Two‐sample pseudo‐score test, variance estimator: Poisson.