Incremental value of diastolic stress test in identifying subclinical heart failure in patients with diabetes mellitus

Abstract

Aims: Resting echocardiography is a valuable method for detecting subclinical heart failure (HF) in patients with diabetes mellitus (DM). However, few studies have assessed the incremental value of diastolic stress for detecting subclinical HF in this population.

Methods and results: Asymptomatic patients with Type 2 DM were prospectively enrolled. Subclinical HF was assessed using systolic dysfunction (left ventricular longitudinal strain <16% at rest and <19% after exercise in absolute value), abnormal cardiac morphology, or diastolic dysfunction (E/e' > 10). Metabolic equivalents (METs) were calculated using treadmill speed and grade, and functional capacity was assessed by percent-predicted METs (ppMETs). Among 161 patients studied (mean age of 59 ± 11 years and 57% male sex), subclinical HF was observed in 68% at rest and in 79% with exercise. Among characteristics, diastolic stress had the highest yield in improving detection of HF with 57% of abnormal cases after exercise and 45% at rest. Patients with revealed diastolic dysfunction during stress had significantly lower exercise capacity than patients with normal diastolic stress (7.3 ± 2.1 vs. 8.8 ± 2.5, P < 0.001 for peak METs and 91 ± 30% vs. 105 ± 30%, P = 0.04 for ppMETs). On multivariable modelling found that age (beta = -0.33), male sex (beta = 0.21), body mass index (beta = -0.49), and exercise E/e' >10 (beta = -0.17) were independently associated with peak METs (combined R2 = 0.46). A network correlation map revealed the connectivity of peak METs and diastolic properties as central features in patients with DM.

Conclusion: Diastolic stress test improves the detection of subclinical HF in patients with diabetes mellitus.

Keywords: diabetic cardiomyopathy; early-stage heart failure; diastolic stress.

Figure 1

Flow chart of the study.

Figure 2

Comparison of systolic and diastolic function at rest and after exercise between controls and patients with DM. (A) The violin plots of resting (black) and after exercise (red) in E/e′ ratio. (B) The change of E/e′ ratio from rest to after exercises. The green circle represents patients in Normal group, the blue circle represents resting diastolic dysfunction group, and the red circle represents patients in revealed diastolic dysfunction group. (C–E) The violin plots resting (black) and after exercise (red) in LVEF (C), LVLS (D), and s′ (E). (F) The ratio of patients with abnormal diastolic and systolic function at rest and after exercise. LVEF, left ventricular ejection fraction; LVLS, left ventricular longitudinal strain.

Figure 3

Prevalence of subclinical HF. (A and B) Venn diagrams demonstrating the overlap between patients with abnormal morphology change (RWT > 0.42 or LV hypertrophy), LV systolic and diastolic dysfunction by only resting echocardiographic assessment (A) as well as adding diastolic stress assessment (B). (C) Prevalence of subclinical HF evaluated by resting echocardiographic assessment, adding contractile reserve, and adding diastolic stress. Adding diastolic stress helped to detect more patients with ≥2 cardiac abnormalities.

Figure 4

(A) Distribution of peak METs and ppMETs. (B) A heatmap showing relationship between exercise capacity and characteristics as well as cardiac function at rest and after exercise. The exercise capacity was more related to cardiac function after exercise compared to that at rest. (C) Independent associates of peak METs. (D) Correlation network. BMI, body mass index; HR, heart rate; LAS, left atrial strain; LVEF, left ventricular ejection fraction; LVLS, left ventricular longitudinal strain; METs, metabolic equivalents; RWT, relative wall thickness; SBP, systolic blood pressure; LAVI, left atrial volume index.