Objectives This study was designed to evaluate the clinical and prognostic aspects of long QT syndrome-related cardiac events that occur in the first year of life (infancy). Background The clinical implications for patients with long QT syndrome who experience cardiac events in infancy have not been studied previously. Methods The study population of 3,323 patients with QTc ≥ 450 ms enrolled in the International LQTS Registry involved 20 patients with sudden cardiac death (SCD), 16 patients with aborted cardiac arrest (ACA), 34 patients with syncope, and 3,253 patients who were asymptomatic during the first year of life. Results The risk factors for a cardiac event among 212 patients who had an ECG recorded in the first year of life included QTc≥500ms, heart rate ≤100bpm, and female sex. ACA before age 1 year was associated with a hazard ratio of 23.4 (p<0.01) for ACA or SCD during age 1-10 years. During the 10-year follow-up after infancy, beta-blocker therapy was associated with a significant reduction in ACA/SCD only in those with a syncopal episode within 2 years before ACA/SCD, but not for those who survived ACA in infancy. Conclusions Patients with LQTS who experience ACA during the first year of life are at very high-risk for subsequent ACA or death during their next 10 years of life, and beta-blockers may not be effective in preventing fatal or near fatal cardiac events in this small but high-risk subset.

Background Patients with long QT syndrome (LQTS) who harbor multiple mutations (i.e. ≥ 2 mutations in ≥ 1 LQTS-susceptibility gene) may experience increased risk for life-threatening cardiac events. Objectives The present study was designed to compare the clinical course of LQTS patients with multiple mutations to those with a single mutation. Methods The risk for life-threatening cardiac events (comprising aborted cardiac arrest, implantable defibrillator shock, or sudden cardiac death) from birth through age 40 years, by the presence of multiple vs. single mutations, was assessed among 403 patients from the LQTS Registry. Results Patients with multiple mutations (n = 57) exhibited a longer QTc at enrollment compared with those with a single mutation (mean ± SD: 506 ± 72 vs. 480 ± 56 msec, respectively; p = 0.003) and had a higher rate of life threatening cardiac events during follow-up (23% vs. 11%, respectively; p < 0.001). Consistently, multivariate analysis demonstrated that patients with multiple mutations had a 2.3-fold (p = 0.015) increased risk for life threatening cardiac events as compared to patients with a single mutation. The presence of multiple mutations in a single LQTS gene was associated with a 3.2-fold increased risk for life threatening cardiac events (p = 0.010) whereas the risk associated with multiple mutation status involving > 1 LQTS gene was not significantly different from the risk associated with a single mutation (HR 1.7, p = 0.26). Conclusions LQTS patients with multiple mutations have a greater risk for life-threatening cardiac events as compared to patients with a single mutation.

Bariatric surgery is a treatment option for obese patients with type 2 diabetes mellitus (T2DM). Although sleeve gastrectomy (SG) is growing in favor, some randomized trials show less weight loss and HbA1c improvement compared with Roux-en-Y gastric bypass (RYGB). The study objective was to compare changes in beta-cell function with similar weight loss after SG and RYGB in obese patients with T2DM. Subjects undergoing SG or RYGB were studied with an intravenous glucose tolerance test before surgery and at 5–12% weight loss post-surgery. The primary endpoint was change in the disposition index (DI). Baseline BMI, HbA1c, and diabetes-duration were similar between groups. Mean total weight loss percent was similar (8.4% ± 0.4, p = 0.22) after a period of 21.0 ± 1.7 days. Changes in fasting glucose, acute insulin secretion (AIR), and insulin sensitivity (Si) were similar between groups. Both groups showed increases from baseline to post-surgery in DI (20.2 to 163.3, p = 0.03 for SG; 31.2 to 232.9, p = 0.02 for RYGB) with no significant difference in the change in DI between groups (p = 0.53). Short-term improvements in beta-cell function using an IVGTT were similar between SG and RYGB. It remains unclear if longer-term outcomes are better after RYGB due to greater weight loss and/or other factors.

Background We evaluated the risk factors and clinical course of Long QT syndrome (LQTS) in African-American patients. Methods The study involved 41 African-Americans and 3,456 Caucasians with a QTc ≥ 450 ms from the U.S. portion of the International LQTS Registry. Data included information about the medical history and clinical course of the LQTS patients with end points relating to the occurrence of syncope, aborted cardiac arrest, or LQTS- related sudden cardiac death from birth through age 40 years. The statistical analyses involved Kaplan-Meier time to event graphs and Cox regression models for multivariable risk factor evaluation. Results The QTc was 29ms longer in African-Americans than Caucasians. Multivarite Cox analyses with adjustment for decade of birth revealed that the cardiac event rate was similar in African-Americans and Caucasians with LQTS and that β-blockers were equally effective in reducing cardiac events in the two racial groups. Conclusions The clinical course of LQTS in African-Americans is similar to that of Caucasians with comparable risk factors and benefit from β-blocker therapy in the two racial groups.

Objectives LV mass (LVM) is widely used to guide clinical decision-making. Cardiac magnetic resonance (CMR) quantifies LVM by planimetry of contiguous short axis images, an approach dependent on reader-selection of images to be contoured. Established methods have applied different binary cutoffs using circumferential extent of LV myocardium to define the basal LV, omitting images containing lesser fractions of LV myocardium. This study tested impact of basal slice variability on LVM quantification. Methods CMR was performed in patients and laboratory animals. LVM was quantified with full inclusion of LV myocardium, and by established methods that use different cutoffs to define the LV basal-most slice: (1) 50% circumferential myocardium at end-diastole alone (ED50), (2) 50% circumferential myocardium throughout both end-diastole and end-systole (EDS50). Results 150 patients and 10 lab animals were studied. Among patients, fully inclusive LVM (172.6±42.3gm) was higher vs. ED50(167.2±41.8gm) and EDS50(150.6±41.1gm; both p<0.001). Methodological differences yielded discrepancies regarding proportion of patients meeting established criteria for LV hypertrophy and chamber dilation (p<0.05). Fully inclusive LVM yielded smaller differences with echocardiography (Δ=11.0±28.8gm) than did ED50 (Δ=16.4±29.1gm) and EDS50 (Δ=33.2±28.7gm, both p<0.001). Among lab animals, ex-vivo LV weight (69.8±13.2gm) was similar to LVM calculated using fully inclusive (70.1±13.5gm, p=0.67) and ED50 (69.4±13.9gm, p=0.70) methods, whereas EDS50 differed significantly (67.9±14.9gm, p=0.04). Conclusions Established CMR methods that discordantly define the basal-most LV produce significant differences in calculated LVM. Fully inclusive quantification, rather than binary cutoffs that omit basal LV myocardium, yields smallest CMR discrepancy with echocardiography-measured LVM and non-significant differences with necropsy-measured LV weight.