Impact of left ventricular longitudinal diastolic functional reserve on clinical outcome in patients with type 2 diabetes mellitus

Background: Left ventricular longitudinal diastolic functional reserve (DFR), as assessed by the change in early diastolic mitral annular velocity (E′) during exercise, is abnormal in patients with type 2 diabetes mellitus (DM). However, the impact of left ventricular longitudinal DFR on clinical outcome has not been explored. This study evaluated the incremental prognostic value of left ventricular DFR in patients with type 2 DM without overt heart disease. Methods: Of 1485 patients who were referred for exercise stress echocardiography, 197 consecutive patients (mean age, 58 years; 84 men) with type 2 DM without overt heart disease were identified. Left ventricular longitudinal DFR was defined as the change in E′ from resting to exercise (ΔE′). The endpoint was a composite of death and hospitalisation for heart failure (HF). Results: During a median follow-up of 57 months (range 6-90), 18 of 197 patients (9.1%) had adverse events (12 deaths, six hospitalisations for HF). Independent predictors of adverse events in a Cox regression analysis were estimated glomerular filtration rate (HR 0.97; 95% CI 0.95 to 0.98; p<0.001), DM duration (HR 1.07; 95% CI 1.01 to 1.14; p=0.018) and ΔE′ (HR 0.58; 95% CI 0.40 to 0.85; p=0.005). In an incremental model, the addition of stress echo data significantly increased the χ² of the clinical and resting left ventricular function model, from 40.5 to 46.6 (p=0.005). Conclusion: Assessment of left ventricular longitudinal DFR during exercise provided incremental prognostic information in patients with type 2 DM without overt heart disease.