Budzikowski, Adam S.

Introduction: Wearable cardiac defibrillators (WCD) have been shown to be effective for detection and treatment of ventricular tachyarrhythmias. However, their efficacy in improving survival or decreasing mortality in patients with newly diagnosed cardiomyopathy (CM) is uncertain. This study reviews the current available evidence. Method: We searched databases since inception to April 2022, without language and year of publication restriction for randomized trials and cohort studies that examined the difference between WCD use and non-use in mortality and survival among patients with ischemic and non-ischemic CM. Two independent investigators screened the abstracts and full texts and extracted the data. Data was analyzed using random effect model. Results: From 603 records identified by a librarian, only 4 randomized trials on WCD use in ischemic CM met the inclusion criteria. One of them was an abstract without any full text published. The total participants were 18,779 of which 2,408 were in the WCD group (mean age 65.12±11.5, 20.7% female) and the rest in control group (mean age 65.45±11.36, 28% female). The adjusted all-cause mortality at 3 months follow up was significantly lower in WCD group (RR 0.32, CI [0.11-0.97], including three studies, 2,360 patients in WCD group and 4,954 in control group) (heterogeneity score I 2 =86%)(figure). Adjusted all-cause mortality at 12 months was also significantly lower in WCD group (RR 0.43, CI [0.25-0.71], two studies, 857 patients in WCD group and 15,566 in control group) (heterogeneity score, I 2 =49%). Only one study reported adjusted risk for arrhythmic death, myocardial infarction, arrhythmia (atrial or ventricular), stroke and hospitalization. In addition, one study reported the difference in cost and healthcare use between the two groups. Conclusion: Our meta-analysis confirms significant reduction in all-cause mortality associated with WCD use in patients with newly diagnosed ischemic cardiomyopathy.

Introduction: This meta-analysis assessed the effect of chronic non-invasive positive airway pressure (> 6 weeks) on moderate to severe OSA with diastolic dysfunction based on echocardiographic parameters. Hypothesis: chronic use of non-invasive positive airway pressure (> 6 weeks) on moderate to severe OSA improves diastolic dysfunction based on echocardiographic parameters. Methods: We searched the databases for randomized clinical trials including Ovid MEDLINE, Ovid Embase Scopus, Web of Science, Google Scholar, and EBSCO CINAHL from inception up to December 20th, 2019. The search was not restricted to time, publication status or language. Two independent investigators screened the identified studies and extracted the data, in duplicate. Risk of bias was assessed using Cochrane collaboration tools. Results: A total of 2753 results were identified. A total of 9 studies including 808 participants were included. Results showed improvement in deceleration time (-39.49ms CI[-57.24,-21.74]; p=0.000), isovolumic relaxation time (-9.32 ms CI[-17.08, -1.57]; p=0.02) and the ratio of early mitral inflow velocity to mitral annular early diastolic velocity (E/E’) (-1.38 CI[-2.6, -0.16]; p=0.03). However, improvement in left atrial volume index, the ratio of early to late mitral inflow velocities (E/A) was not statistically significant. The risk of bias is mild to moderate. Conclusions: Our results suggest that chronic treatment of moderate to severe OSA with non-invasive positive airway pressure is associated with improvement in diastolic dysfunction.