Robert C. Bahler

Objective: To perform a systematic review of studies evaluating pharmacologic therapies for the cardiomyopathy of Duchenne muscular dystrophy (DMD). Methods: PubMed, Google Scholar, and Embase were searched through October 8, 2020. Articles were selected using pre‐determined criteria; 26 underwent detailed review by two co‐authors. Study quality was assessed with the Newcastle–Ottawa scoring system (NOS); GRADE assessment evaluated their overall clinical importance.Results: There were few randomized controlled trials. Two of four trials of angiotensin converting enzyme inhibitors (ACEI) or ACEI plus beta‐blockers (BB) found improved LV function. Two of two randomized trials of aldosterone antagonists (AA), when added to ACEI and BB therapy, demonstrated less decline of LV circumferential strain over 1 year of treatment. Observational studies of ACEI and BB had differing patient ages, symptomatology, cohort size, study duration and baseline heart function. LV function, assessed via unblinded imaging, was the most frequent outcome measure. LV dysfunction improved in some trials but was unconfirmed in others. Class IV heart failure patients had transient improvement of symptoms and LVEF. Most NOS scores reflected a low level of study quality. The Grade certainty rating, used for the summation of studies, was between “low” and “moderate.”Conclusion: Randomized trial evidence was inconsistent that either ACEI or BB or their combination improve LV function and/or alter progressive LV dysfunction. When ACEI and BB therapy are initiated for symptomatic Class IV heart failure, symptoms and LVEF improve transiently. AAs retard the rate of decline of LV function when initiated in younger DMD patients.

Background Ischemia-reperfusion injury (IRI) frequenting follows successful PCI for STEMI and is recognized by multiple modalities. Multilayer speckle tracking echocardiography (STE) has the potential of detecting myocardial dysfunction in different myocardial layers. Our objective was to describe the changes in layer-specific myocardial function over the 24 hours after successful PCI for ST-elevation myocardial infarction (STEMI). Methods Patients (n = 120) with STEMI and no prior myocardial infarction underwent echocardiography prior to PCI, immediately after and at 3- and 24-hours post-PCI. Worsening focal dysfunction (WFD) was defined as an immediate reduction, compared to the pre-PCI value, in the amplitude of endo-myocardial longitudinal strain (endo-MLS) within the infarction territory. Results Patients with WFD (52%) had further reductions in endo-MLS, mid-MLS, and epi-MLS in the infarction region immediately post-PCI; at 3 hours strain began to improve and continued to improve at 24 hours. Reductions of endo-MLS strain were more evident than those of global, mid-MLS, and epi-MLS. This same pattern was seen in each of the ischemic territories of the anterior descending, circumflex, and right coronary arteries. Immediate improvement in endo-MLS following PCI was seen in 48% of patients. The time from symptom onset to balloon time was markedly longer in those with WFD (P < .0001). Conclusions Multilayer SPE is a sensitive method that identifies serial alterations in focal myocardial function following successful PCI for STEMI. Layer-specific reductions in endo-MLS appeared more evident than decreases in global LV strain. Prolonged total ischemic time prior to PCI was directly related to the incidence of WFD.

Background: Assessment of left ventricular (LV) diastolic function is part of routine echocardiographic examinations. Accuracy of the 2016 ASE/EACVI algorithm to detect LV diastolic dysfunction in patients with a normal LV ejection fraction (LVEF) has been examined but simultaneous measurements of LV pressures and echocardiographic parameters of diastolic function are sparse.Methods: The accuracy of multiple echo parameters of diastolic dynamics and the 2016 guidelines were assessed by simultaneous transthoracic echocardiography and LV pressure recordings in 120 patients (derivation cohort) and 60 patients (validation cohort) with suspected coronary artery disease and normal LVEF. Receiver‐operating characteristic (ROC) curves defined optimal cut points for each echocardiographic parameter. A new algorithm was proposed to estimate LV diastolic pressures using 5 parameters based on ROC data: tricuspid regurgitation velocity >280cm/s, average e' 13, velocity of pulmonary vein A‐wave reversal >32 cm/s, and left atrial volume index >32 mL/m². Performances of the 2016 guidelines and a proposed algorithm were examined for detecting a LV pre‐A >12 and LV end‐diastolic pressure (LVEDP) >15 mm Hg.Results: In the derivation cohort, the 2016 algorithm identified an elevated LVEDP >15 mm Hg with an accuracy of 74.2% (63.8–82.9); the modified algorithm improved accuracy to 86.0% (77.6–92.1), P < .05. In the validation cohort, the proposed algorithm improved sensitivities with accuracies remaining like the 2016 algorithm.Conclusions: LV diastolic pressures in patients with normal LVEF were reliably assessed by the 2016 guidelines. The proposed algorithm improved sensitivities and may improve the accuracies for detecting abnormal LV filling pressures.

Background: The myocardial structure differs between secondary left ventricular hypertrophy (LVH) and hypertrophic cardiomyopathy (HCM). We investigated left ventricular function of these two types of hypertrophy using multilayer strain analysis with two‐dimensional echocardiography.Methods: Transthoracic echocardiography (Vivid‐E9) was performed in 240 patients with preserved left ventricular ejection fraction (LVEF ≥50%) and with either HCM (n = 80, 63 men, age 49.8 ± 14.1 years), hypertensive LVH (n = 80, 63 men, age 51.4 ± 13.3 years) or normal blood pressure and left ventricular structure (n = 80, 63 men, 50.8 ± 12.4 years). Quantitative multilayer longitudinal strain (LS), circumferential strain (CS), and radial strain (RS) were analyzed. The ratio of endo‐/epi‐myocardial strain was calculated.Results: Longitudinal strain was significantly (P < 0.001) lower in HCM patients than normal controls (15.2 ± 4.2% vs 23.1 ± 2.7%), especially in hypertrophic segments (14.5 ± 4.4% vs 17.2 ± 3.2% in nonhypertrophic segments, P < 0.01). LS was lower in patients with hypertensive LVH, similarly in all left ventricular segments (20.7 ± 3.7%, P < 0.001 vs controls). CS was lower in the mid‐ and epicardium (P < 0.01), but not endocardium in HCM (P = 0.4), and preserved in all myocardial layers in hypertensive LVH. The endo‐/epi‐myocardial ratios of both LS and CS were higher in HCM than hypertensive LVH (P < 0.01). RS was higher (P < 0.01) in HCM than hypertensive LVH and controls. Endocardial CS and global RS were correlated with LVEF (r ≥ 0.32, P < 0.01).Conclusions: Hypertrophic cardiomyopathy patients had marked reductions in LS and CS, whereas patients with hypertensive LVH had less reduction in LS and preserved CS. The increased endo‐/epi‐myocardial ratios of LS and CS may be useful in differentiating HCM from hypertensive LVH.

Commentary: Predicting Outcomes in Patients with Asymptomatic Moderate to Severe Aortic Stenosis, Journal of Cardiology and Cardiovascular Sciences

Objective To describe the natural history of cardiomyopathy in patients with Duchenne muscular dystrophy (DMD) who are receiving contemporary therapies. Methods This is a single-institution retrospective cohort study of 57 patients aged >15 years with DMD. Serial digital echocardiograms were performed over a median follow-up of 8 years. Left ventricular dysfunction (LVD) was defined as shortening fraction (SF) Results The SF declined progressively in 53/57 patients (93%). LVD occurred in 40 of 57 patients (70%), with variable age at onset (median 18 years, IQR 14–21.5 years). Rate of SF decline (–1.51%±1.16%/year) was variable and unrelated to genotype. However, survival was shorter for patients with LVD onset at age Conclusion Despite contemporary therapies, SF declined progressively in almost all patients. Age at onset of LVD and age at death were variable and unrelated to genotype; however, survival was shortened for patients with LVD onset at age <18 years. Death was usually preceded by LVD. CHF was a sentinel event, with death occurring shortly thereafter.