AimsAlthough dipyridamole is a widely used pharmacological stress agent, the direct effects on myocardium are not entirely known. Diabetic cardiomyopathy can be investigated by 2D-strain echocardiography. The aim of this study was to assess myocardial functional reserve after dipyridamole infusion using speckle-tracking echocardiography.MethodsSeventy-five patients referred for dipyridamole stress myocardial perfusion gated SPECT (MPGS) were examined by echocardiography to assess a new concept of longitudinal strain reserve (LSR) and longitudinal strain rate reserve (LSRR) respectively defined by the differences of global longitudinal strain (GLS) and longitudinal strain rate between peak stress after dipyridamole and rest. Twelve patients with myocardial ischemia were excluded on the basis of MPGS as gold standard.ResultsMean LSR was −2.28±2.19% and was more important in the 28 (44%) diabetic patients (−3.27±1.93%; p = 0.001). After multivariate analyses, only diabetes improved LSR (p = 0.011) after dipyridamole infusion and was not associated with glycaemic control (p = 0.21), insulin therapy (p = 0.46) or duration of the disease (p = 0.80). Conversely, age (p = 0.002) remained associated with a decrease in LSR. LSSR was also correlated to age (p = 0.005). Patients with a LSR < 0% have a better survival after 15 months (log-rank p = 0.0012).ConclusionLSR explored by 2D speckle-tracking echocardiography after dipyridamole infusion is a simple and new concept that provides new insights into the impact of diabetes and age on the myocardium with a potential prognostic value.

BackgroundEpidemiological and observational studies have established that high-density lipoprotein cholesterol (HDL-C) is an independent negative cardiovascular risk factor. However, simple measurement of HDL-C levels is no longer sufficient for cardiovascular risk assessment. Therefore, there is a critical need for novel non-invasive biomarkers that would display prognostic superiority over HDL-C. Cell surface ecto-F1-ATPase contributes to several athero-protective properties of HDL, including reverse cholesterol transport and vascular endothelial protection. Serum inhibitory factor 1 (IF1), an endogenous inhibitor of ecto-F1-ATPase, is an independent determinant of HDL-C associated with low risk of coronary artery disease (CAD). This work aimed to examine the predictive value of serum IF1 for long-term mortality in CAD patients. Its informative value was compared to that of HDL-C.MethodSerum IF1 levels were measured in 577 male participants with stable CAD (age 45–74 years) from the GENES (Genetique et ENvironnement en Europe du Sud) study. Vital status was yearly assessed, with a median follow-up of 11 years and a 29.5 % mortality rate. Cardiovascular mortality accounted for the majority (62.4 %) of deaths.ResultsIF1 levels were positively correlated with HDL-C (rs = 0.40; P < 0.001) and negatively with triglycerides (rs = −0.21, P < 0.001) and CAD severity documented by the Gensini score (rs = −0.13; P < 0.01). Total and cardiovascular mortality were lower at the highest quartiles of IF1 (HR = 0.55; 95 % CI, 0.38–0.89 and 0.50 (0.28–0.89), respectively) but not according to HDL-C. Inverse associations of IF1 with mortality remained significant, after multivariate adjustments for classical cardiovascular risk factors (age, smoking, physical activity, waist circumference, HDL-C, dyslipidemia, hypertension, and diabetes) and for powerful biological and clinical variables of prognosis, including heart rate, ankle-brachial index and biomarkers of cardiac diseases. The 10-year mortality was 28.5 % in patients with low IF1 (<0.42 mg/L) and 21.4 % in those with high IF1 (≥0.42 mg/L, P < 0.02).ConclusionsWe investigated for the first time the relation between IF1 levels and long-term prognosis in CAD patients, and found an independent negative association. IF1 measurement might be used as a novel HDL-related biomarker to better stratify risk in populations at high risk or in the setting of pharmacotherapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-016-0672-9) contains supplementary material, which is available to authorized users.

The poorer functional evaluations in iron-deficient patients previously reported are not caused by the merging of two different populations (i.e. patients with absolute or relative iron deficiency). Our study has confirmed that non-anaemic HF patients with AID have poorer peak oxygen consumption. However, AID has no impact on the survival of these patients.