This novel cumulative ECG risk score was independently associated with SCD and was particularly effective for LVEF >35% where risk stratification is currently unavailable. These findings warrant further evaluation in prospective clinical investigations.

Background The goal of this study is to report the characteristics and long‐term clinical outcomes of patients with spontaneous coronary artery dissection (SCAD) and to identify factors associated with recurrent SCAD . Methods and Results This is a retrospective cohort study that included patients who underwent coronary angiography for evaluation of acute myocardial infarction between 2006 and 2016. Among 26 598 patients hospitalized with a principal diagnosis of acute myocardial infarction, 208 (0.78%) were diagnosed with SCAD . Patients with SCAD were younger (49.0±11.6 versus 65.6±12.2 years) and more likely to be women (88.9% versus 31.6%). Atherosclerotic risk factors, such as hypertension, hyperlipidemia, obesity, and diabetes mellitus, were less prevalent. Median follow‐up was 4.7 years. Mortality was lower in patients with SCAD (1‐year mortality: 2.4% versus 8.8%; P <0.001). After using propensity score matching to control for differences in age, sex, and comorbidities, the difference in mortality was no longer present, suggesting that lower mortality in patients with SCAD is attributed primarily to their baseline characteristics. Recurrent SCAD occurred in 22 patients (10.6%). Multivariate Cox regression modeling showed concomitant fibromuscular dysplasia (hazard ratio, 5.1; 95% CI , 1.6–15.8; P =0.005) and migraine headaches (hazard ratio, 3.4; 95% CI , 1.4–8.4; P =0.008) to be associated with increased risk of recurrent SCAD . Conclusions Among patients with acute myocardial infarction, patients with SCAD have a lower risk of mortality, which is attributed primarily to their younger age, female sex, and low prevalence of atherosclerotic risk factors. Risk of recurrent SCAD persists years after the initial presentation. Patients with fibromuscular dysplasia and migraine are at higher risk for recurrent SCAD .

Objective To compare four heart rate correction formulas for calculation of the rate corrected QT interval (QTc) among infants and young children. Study design R and QT intervals were measured from digital electrocardiograms. QTc were calculated with the Bazett, Fridericia, Hodges, and Framingham formulas. QTc versus RR graphs were plotted, and slopes of the regression lines compared. Slopes of QTc-RR regression lines close to zero indicate consistent QT corrections over the range of heart rates. Results We reviewed electrocardiograms from 702 children, with 233 (33%) <1 year of age and 567 (81%) <2 years. The average heart rate was 122 ±20 bpm (median 121 bpm). The slopes of the QTc-RR regression lines for the four correction formulas were: −0.019 (Bazett); 0.1028 (Fridericia); −0.1241 (Hodges); and 0.2748 (Framingham). With the Bazett formula, a QTc >460 ms was 2 standard deviations above the mean, compared with “prolonged” QTc values of 414, 443, and 353 ms for the Fridericia, Hodges, and Framingham formulas, respectively. Conclusions The Bazett formula calculated the most consistent QTc; 460 msec is the best threshold for prolonged QTc. The study supports continued use of the Bazett formula for infants and children and differs from the use of the Fridericia correction during clinical trials of new medications.

BACKGROUND/OBJECTIVES: Older patients are underrepresented in acute coronary syndrome clinical trials. We sought to evaluate the benefits of revascularization in patients aged 80 years and older presenting with acute myocardial infarction (AMI). DESIGN: Retrospective study utilizing inverse probability of treatment weighting (IPTW). SETTING: Single tertiary referral center for an integrated healthcare system in southern California. PARTICIPANTS: Patients undergoing invasive coronary angiography for AMI between 2009 and 2019, and subsequently treated with percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), or medical therapy alone. MEASUREMENTS: All-cause mortality, nonfatal myocardial infarction (MI), and repeated revascularization. RESULTS: A total of 1,433 patients aged 80 years or older (median age = 83.5 years; 66% male) presenting with AMI who underwent treatment with PCI (50%), CABG (12%), or medical therapy alone (38%) were included. Those treated with medical therapy were more likely to be Black, had one or more chronic total occlusions in any vessel, had more comorbidities, and had lower left ventricular ejection fraction. Baseline characteristics were well balanced after IPTW adjustment. Median follow-up was 2.6 years. Revascularization (PCI or CABG) was associated with reduced mortality (hazard ratio (HR) = 0.66; 95% confidence interval (CI) = 0.60-0.73) and nonfatal MI (HR = 0.68; 95% CI = 0.58-0.78), but an increased need for repeated revascularization (HR = 1.60; 95% CI = 1.15-2.23). Separately comparing PCI or CABG alone versus medical therapy yielded similar results. Revascularization was associated with lower mortality in all subgroups, except in Black patients and those with prior CABG. CONCLUSION: Revascularization is superior to medical therapy in reducing all-cause mortality and nonfatal MI in patients aged 80 years and older with AMI. Age alone should not preclude patients from potentially beneficial invasive therapies.