The Morphology of Coronary Artery Disease in South Asians vs White Caucasians and Its Implications.

South Asians (SAs) experience a higher prevalence and earlier onset of coronary artery disease and have worse outcomes compared with White Caucasians (WCs) following invasive revascularisation procedures, a mainstay of coronary artery disease (CAD) management. We sought to review the differences in the CAD pattern and risk factors between SA and WC patients and to discuss their potential impact on the development of coronary disease, acute coronary syndrome, and revascularisation outcomes. SAs have a more diffuse pattern with multivessel involvement compared with WCs. However, less is known about other morphologic characteristics, such as calcification of atherosclerotic plaque and coronary diameter in SA populations. Despite a similar coronary calcification burden, higher noncalcified plaque composition, elevated thrombosis, and inflammatory markers likely contribute to the disease pattern. Although the current evidence on the role of coronary vessel size remains inconsistent, smaller diameters in SAs could play a potential role in the higher disease prevalence. This is especially important given the impact of coronary artery diameter on revascularisation outcomes. In conclusion, SAs have a unique CAD risk profile composed of traditional and novel risk factors. Our findings highlight the need for additional awareness of health professionals of this specific risk profile and potential therapeutic targets, as well as the need for further research in this vulnerable population.

Care and Outcomes of ST-Segment Elevation Myocardial Infarction Across Multiple COVID-19 Waves.

BACKGROUND: There are concerns of delays in ST-segment elevation myocardial infarction (STEMI) care during the COVID-19 pandemic. It is unclear whether the care and outcomes of STEMI patients differ between COVID-19 waves and compared with historical periods. METHODS: Consecutive patients in the Vancouver Coastal Health Authority STEMI database were included to compare care during 3 distinct waves of the COVID-19 pandemic (9 months; March 2020 to January 2021) with an historical non-COVID-19 cohort. We compared STEMI incidence, baseline characteristics, and outcomes between groups. We also examined time from first medical contact (FMC) to reperfusion, symptom to FMC, and FMC to STEMI diagnosis, as well as predictors of delays. RESULTS: The incidence of STEMI was similar during COVID-19 (n = 305; mean 0.93/day) and before COVID-19 (n = 949; 0.97/day; P = 0.80). The COVID-19 cohort showed significant delay in FMC-to-reperfusion (median 116 min vs 102 min; P < 0.001) and FMC-to-STEMI diagnosis (median 17 mins vs 11 min; P < 0.001). Delays in FMC-to-device times worsened across the 3 COVID-19 waves (FMC-to-device time ≤ 90 min in wave 1: 32.9%; in wave 2: 25.6%; in wave 3: 16.3%; P = 0.045 [47.5% before COVID-19; P < 0.001]). There were no significant predictors of delay were unique to the COVID-19 cohort. CONCLUSIONS: This study demonstrates delays in reperfusion during the COVID-19 pandemic compared with the historical control, with delays increasing during subsequent waves within the pandemic. It is critical to further understand these care gaps to improve STEMI care for future waves of the current and future pandemics.

Impact of oral soluble guanylate cyclase stimulators in heart failure: A systematic review and Meta-analysis of randomized controlled trials.

BACKGROUND: Soluble guanylate cyclase (sGC) stimulators are a novel class of medications with emerging role in heart failure (HF). The aim of this study is to evaluate the efficacy and safety of oral sGC stimulators in patients with HF with reduced and preserved ejection fraction (HFrEF and HFpEF) by pooling data from all available randomized control trials (RCT). METHODS: A comprehensive search of electronic databases from 2000-2020 was performed. Seven RCTs, three HFrEF and four HFpEF studies, were identified. The follow-up duration ranged from 1 month to a median of 10.8 months. A random-effects meta-analysis was conducted to summarize the studies. RESULTS: The study population included 7190 patients: 5707 HFrEF and 1483 HFpEF patients. In HFrEF, oral sGC stimulators reduced the composite incidence of HF hospitalization and cardiovascular death (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.78-0.97; I2 = 0%), primarily driven by lower HF hospitalization (HR 0.88, 95% CI 0.78-0.99; I2 = 0%). There was no significant reduction in all-cause death in HFrEF (HR 0.95, 95% CI 0.83-1.09; I2 = 0%). In HFpEF, there were no improvements in Kansas City Cardiomyopathy Questionnaire clinical summary scores (mean difference 0.81, 95% CI -2.16-3.77; I2 = 72%) or 6-minute walk distance (mean difference 3.34 meters, 95% CI -7.86-14.54; I2 = 28%). There was no difference in all-cause mortality in HFpEF (HR 1.94, 95% CI 0.92-4.09; I2 = 0%). Overall, oral sGC stimulators had low medication-related serious adverse events. CONCLUSION: Oral sGC stimulators are well tolerated in HF and reduce the incidence of HF hospitalization but not cardiovascular death among patients with HFrEF. However, there are no apparent benefits in HFpEF.

Door-to-Targeted Temperature Management Initiation Time and Outcomes in Out-of-Hospital Cardiac Arrest: Insights From the Continuous Chest Compressions Trial.

Background Targeted temperature management ( TTM ) is a recommended treatment modality to improve neurological outcomes in patients with out-of-hospital cardiac arrest. The impact of the duration from hospital admission to TTM initiation (door-to- TTM ; DTT ) on clinical outcomes has not been well elucidated. We hypothesized that shorter DTT initiation intervals would be associated with improved survival with favorable neurological outcome. Methods and Results We performed a post hoc analysis of nontraumatic paramedic-treated out-of-hospital cardiac arrests. The primary outcome was favorable neurological status at hospital discharge, with a secondary outcome of survival to discharge. We fit a logistic regression analysis to determine the association of early compared with delayed DTT , dichotomized by the median DTT duration, and outcomes. Of 3805 patients enrolled in the CCC (Continuous Chest Compressions) Trial in British Columbia, 570 were included in this analysis. There was substantial variation in DTT among patients receiving TTM . The median DTT duration was 122 minutes (interquartile range 35-218). Favorable neurological outcomes in the early and delayed DTT groups were 48% and 38%, respectively. Compared with delayed DTT (interquartile range 167-319 minutes), early DTT (interquartile range 20-81 minutes) was associated with survival (adjusted odds ratio 1.56, 95% CI 1.02-2.38) but not with favorable neurological outcomes (adjusted odds ratio 1.45, 95% CI , 0.94-2.22) at hospital discharge. Conclusions There was wide variability in the initiation of TTM among comatose out-of-hospital cardiac arrest survivors. Initiation of TTM within 122 minutes of hospital admission was associated with improved survival. These results support in-hospital efforts to achieve early DTT among out-of-hospital cardiac arrest patients admitted to the hospital.

Challenge and Impact of Quinidine Access in Sudden Death Syndromes: A National Experience.

OBJECTIVES: This study sought to determine the nature of quinidine use and accessibility in a national network of inherited arrhythmia clinics. BACKGROUND: Quinidine is an antiarrhythmic medication that has been shown to be beneficial in select patients with Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation. Because of the low prevalence of these conditions and restricted access to quinidine through a single regulatory process, quinidine use is rare in Canada. METHODS: Subjects prescribed quinidine were identified through the Hearts in Rhythm Organization that connects the network of inherited arrhythmia clinics across Canada. Cases were retrospectively reviewed for patient characteristics, indications for quinidine use, rate of recurrent ventricular arrhythmia, and issues with quinidine accessibility. RESULTS: In a population of 36 million, 46 patients are currently prescribed quinidine (0.0000013%, age 48.1 ± 16.1 years, 25 are male). Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation constituted a diagnosis in 13 subjects (28%), 6 (13%), and 21 (46%), respectively. Overall, 37 subjects (81%) had cardiac arrest as an index event. After initial presentation, subjects experienced 7.47 ± 12.3 implantable cardioverter-defibrillator shocks prior to quinidine use over 34.3 ± 45.9 months, versus 0.86 ± 1.69 implantable cardioverter-defibrillator shocks in 43.8 ± 41.8 months while on quinidine (risk ratio: 8.7, p < 0.001). Twenty-two patients access quinidine through routes external to Health Canada's Special Access Program. CONCLUSIONS: Quinidine use is rare in Canada, but it is associated with a reduction in recurrent ventricular arrhythmias in patients with Brugada syndrome, early repolarization syndrome, and idiopathic ventricular fibrillation, with minimal toxicity necessitating discontinuation. Drug interruption is associated with frequent breakthrough events. Access to quinidine is important to deliver this potentially lifesaving therapy.

Early Repolarization Pattern Inheritance in the Cardiac Arrest Survivors With Preserved Ejection Fraction Registry (CASPER).

OBJECTIVES: This study explored early repolarization (ER) pattern inheritance between survivors of unexplained cardiac arrest (UCA) and their first-degree relatives. BACKGROUND: ER is considered a factor that confers an increased risk of sudden death. A monogenic explanation for ER is seldom evident after cascade screening. METHODS: UCA survivors and their first-degree relatives enrolled in the CASPER (Cardiac Arrest Survivors With Preserved Ejection Fraction Registry) were included in the study. ER was defined and characterized according to accepted criteria. Logistic regression was performed to explore the association between ER status in the UCA survivor and first-degree relative groups based on the presence of an ER pattern in their related family members after adjusting for age, sex, and ethnicity. RESULTS: A total of 289 patients from 14 Canadian sites were studied (age: 43.0 ± 15.9 years; 148 women), and 945 electrocardiograms were analyzed. Seventy-five patients had the ER pattern. There was a significantly higher prevalence of the ER pattern in UCA survivors who had first-degree relatives with the ER pattern (adjusted odds ratio: 5.79; 95% confidence intervals [CIs]: 1.79 to 18.7). There was also a nonsignificant higher prevalence of the ER pattern in first-degree relatives of UCA survivors with the ER pattern (OR: 2.43; 95% CI: 0.70 to 8.43). The highest prevalence of the ER pattern was seen in first-degree relatives of UCA survivors with ER syndrome (29%). CONCLUSIONS: The ER pattern appeared to be more common among UCA survivors and first-degree relatives whose related family members had similar changes on electrocardiography, which suggested that genetically complex factors contribute to electrocardiographic patterns that predispose to cardiac arrest.