Fast assessment of long axis strain with standard cardiovascular magnetic resonance: a validation study of a novel parameter with reference values

Background: Assessment of longitudinal function with cardiovascular magnetic resonance (CMR) is limited to measurement of systolic excursion of the mitral annulus (MAPSE) or elaborate strain imaging modalities. The aim of this study was to develop a fast assessable parameter for the measurement of long axis strain (LAS) with CMR. Methods: 40 healthy volunteers and 125 patients with different forms of cardiomyopathy were retrospectively analyzed. Four different approaches for the assessment of LAS with CMR measuring the distance between the LV apex and a line connecting the origins of the mitral valve leaflets in enddiastole and endsystole were evaluated. Values for LAS were calculated according to the strain formula. Results: LAS derived from the distance of the epicardial apical border to the midpoint of the line connecting the mitral valve insertion points (LAS-epi/mid) proved to be the most reliable parameter for the assessment of LAS among the different approaches. LAS-epi/mid displayed the highest sensitivity (81.6 %) and specificity (97.5 %), furthermore showing the best correlation with feature tracking (FTI) derived transmural longitudinal strain (r = 0.85). Moreover, LAS-epi/mid was non-inferior to FTI in discriminating controls from patients (Area under the curve (AUC) = 0.95 vs. 0.94, p = NS). The time required for analysis of LAS-epi/mid was significantly shorter than for FTI (67 ± 8 s vs. 180 ± 14 s, p < 0.0001). Additionally, LAS-epi/mid performed significantly better than MAPSE (Delta AUC = 0.09; p < 0.005) and the ejection fraction (Delta AUC = 0.11; p = 0.0002). Reference values were derived from 234 selected healthy volunteers. Mean value for LAS-epi/mid was −17.1 ± 2.3 %. Mean values for men were significantly lower compared to women (−16.5 ± 2.2 vs. -17.9 ± 2.1 %; p < 0.0001), while LAS decreased with age. Conclusions: LAS-epi/mid is a novel and fast assessable parameter for the analysis of global longitudinal function with non-inferiority compared to transmural longitudinal strain

Diabetic cardiomyopathy

Diabetic cardiomyopathy is a distinct primary disease process, independent of coronary artery disease, which leads to heart failure in diabetic patients. Epidemiological and clinical trial data have confirmed the greater incidence and prevalence of heart failure in diabetes. Novel echocardiographic and MR (magnetic resonance) techniques have enabled a more accurate means of phenotyping diabetic cardiomyopathy. Experimental models of diabetes have provided a range of novel molecular targets for this condition, but none have been substantiated in humans. Similarly, although ultrastructural pathology of the microvessels and cardiomyocytes is well described in animal models, studies in humans are small and limited to light microscopy. With regard to treatment, recent data with thiazoledinediones has generated much controversy in terms of the cardiac safety of both these and other drugs currently in use and under development. Clinical trials are urgently required to establish the efficacy of currently available agents for heart failure, as well as novel therapies in patients specifically with diabetic cardiomyopathy

Global 2-Dimensional Strain as a New Prognosticator in Patients With Heart Failure

Objectives: We sought to evaluate whether global 2-dimensional (2D) strain offers additional benefit over left ventricular ejection fraction (LVEF) to predict clinical events in heart failure. Background: Although 2D strain based on speckle tracking has been proposed as a simple and reproducible tool to detect systolic dysfunction, the relationship of 2D strain and prognosis has not been studied. Methods: Two hundred one patients (age 63 ± 11 years, 34% female, LVEF 34 ± 13%) hospitalized for acute heart failure underwent clinical evaluation and conventional and tissue Doppler echocardiography. Using dedicated software, we measured the global longitudinal strain (GLS) in apical 4- and 2-chamber views and the global circumferential strain (GCS) in a parasternal short-axis view. Cardiac events were defined as readmission for heart failure or cardiac death. Results: There were 23.4% clinical events during 39 ± 17 months of follow-up. In univariate analysis, age, left atrial volume, left ventricular volume, LVEF, ratio of early transmitral flow to early diastolic annular velocity (E/e′), and both GLS and GCS were predictive of cardiac events. In multivariate Cox models, age (hazard ratio [HR]: 1.06, 95% confidence interval [CI]: 1.01 to 1.10, p = 0.017) and GCS (HR: 1.15, 95% CI: 1.04 to 1.28; p = 0.006) were independently associated with cardiac events. By Cox proportional hazards model, the addition of GCS markedly improved the prognostic utility of a model containing ejection fraction, E/e′, and GLS. Conclusions: GCS is a powerful predictor of cardiac events and appears to be a better parameter than ejection fraction in patients with acute heart failure