Journal of the American College of Cardiology最新文献

Background: Atrial fibrillation (AF), the most common cardiac arrhythmia, is a major cause of stroke and often remains undiagnosed due to its paroxysmal and frequently asymptomatic nature. Wearables provide a scalable, noninvasive screening tool.

Objectives: This trial evaluated new onset AF detection in patients at elevated stroke risk using remote smartwatch-based screening.

Methods: This prospective multicenter randomized controlled trial included patients ≥65 years with elevated stroke risk (CHA₂DS₂-VASc ≥2 men, ≥3 women) from 2 secondary care centers in the Netherlands. Patients were randomized to 6-month (180-day) monitoring with a smartwatch with photoplethysmography and single-lead electrocardiogram (ECG) functions, or standard care. ECGs were reviewed remotely by an independent eHealth team within 24 hours. The primary outcome was new onset AF, defined as a confirmed episode lasting ≥30 seconds on single-lead ECG or standard ECG methods.

Results: Between November 2022 and December 2023, 437 patients were randomized (219 intervention, 218 control); the median age was 75 years, 46.7% were female and the median CHA₂DS₂-VASc score was 3.0. New onset AF occurred in 21 (9.6%) patients of the intervention group and 5 (2.3%) patients of the control group (risk difference: 7.3 percentage points; 95% CI: 2.9-11.7 percentage points; P = 0.001; HR: 4.40; 95% CI: 1.66-11.66). Several asymptomatic AF episodes were detected only in the intervention group, while paroxysmal AF occurred in both groups.

Conclusions: This randomized controlled trial provides evidence that 6-month smartwatch-based AF screening enhances the detection rate of new onset AF compared with standard care in patients at elevated stroke risk. (Detection and Quantification of Atrial Fibrillation in High-risk Patients Using a Smartwatch Wearable [Apple Watch] [EQUAL]; NCT05686330).

Background: Out-of-hospital cardiac arrest (OHCA) is a major global health issue. For patients without ST-segment elevation after return of spontaneous circulation, the COACT (Coronary Angiography After Cardiac Arrest) trial was the first randomized trial that investigated the benefit of immediate vs delayed coronary angiography with subsequent percutaneous coronary intervention if needed. No difference in 90-day survival was found. The long-term impact on survival of the 2 treatment strategies remains uncertain.

Objectives: The aim of this study was to investigate the 5-year impact on survival of immediate vs delayed coronary angiography in OHCA patients with an initial shockable rhythm and no ST-segment elevation on initial electrocardiography after return of spontaneous circulation.

Methods: The COACT trial was a randomized, open-label, multicenter study comparing immediate vs delayed coronary angiography in patients resuscitated from OHCA without ST-segment elevation. Nineteen Dutch centers enrolled patients, and 5-year follow-up was obtained via structured telephone interviews. Secondary endpoints included myocardial infarction, repeat revascularization, heart failure-related hospitalizations, and implantable cardioverter-defibrillator shocks.

Results: At 5-year follow-up, data from 514 of 552 patients (93.1%) were available. Of these patients, 261 (50.8%) were assigned to immediate angiography and 253 (49.2%) to a delayed strategy. Baseline characteristics were similar across the 2 treatment groups. Five years after the index hospitalization, 143 patients (54.8%) were alive in the immediate angiography group, and 131 patients (51.8%) were alive in the delayed angiography group (HR: 0.95; 95% CI: 0.74-1.23; log-rank P = 072). In a nonprespecified and exploratory landmark analysis, HRs for death to 90 days and >90 days were 1.11 (95% CI: 0.84-1.49; log-rank P = 0.46) and 0.56 (95% CI: 0.32-0.97; log-rank P = 0.04). Rates of myocardial infarction, heart failure-related hospitalization, and revascularization were low and did not differ between groups.

Conclusions: At 5 years, survival was comparable between immediate and delayed angiography, with no clear benefit or harm. A late survival benefit appeared after 90 days, though its clinical significance remains uncertain and most likely is due to chance. (Coronary Angiography After Cardiac Arrest [COACT]; NTR4973).

Background: Many patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) have devices capable of right ventricular pacing (RVP). Although pacing can reduce left ventricular outflow tract gradient (LVOTg), it can also reduce cardiac output, so its net effect is variable.

Objectives: We tested whether electromechanical optimization of the programmed atrio-ventricular delay (AVD) allows RVP to achieve a net benefit on symptoms.

Methods: EMORI-HCM (Electromechanically Optimized Right Ventricular Pacing in Obstructive Hypertrophic Cardiomyopathy) is a multicenter, blinded, randomized, crossover trial of AVD-optimized RVP in patients with symptomatic oHCM with resting or provoked gradient of at least 30 mm Hg. Patients with existing dual-chamber devices were randomized to either 3 months of continuous AVD-optimized RVP (intervention) followed by 3 months of backup-only RVP (control), or vice versa. AVD was optimized using a high-precision multiple-alternation protocol assessing acute change in beat-by-beat blood pressure while varying AVD. The primary outcome was symptoms measured by the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score. Secondary outcomes include patient-reported daily symptom data collected using a dedicated smartphone application (ORBITA-app), dichotomous patient preference, EQ-5D, exercise capacity, and LVOTg. Patients were blinded to treatment allocation. Symptom assessments were self-administered. Outcome measures were recorded at baseline, crossover, and completion. Analysis was by Bayesian ordinal mixed modeling.

Results: Between October 2021 and October 2024, 117 screened patients met the inclusion criteria, of whom 60 were randomized. AVD-optimized RVP improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (+4.5; 95% credible interval [CrI]: 1.3-8.1; probability of benefit [Pr_benefit] = 0.997) and daily symptom scores (OR: 1.29; 95% CrI: 0.98-1.68; Pr_benefit: 0.969) compared with backup-only pacing. AVD-optimized RVP improved exercise capacity (+1.0 mL/kg/min; 95% CrI: 0.1-2.0; Pr_benefit: 0.984) and LVOTg (-7.3 mm Hg; 95% CrI: -13.5 to -1.1; Pr_benefit: 0.010). It had no effect on B-type natriuretic peptide (Pr_benefit: 0.893) and ejection fraction was preserved (Pr_benefit: 0.409).

Conclusions: In patients with oHCM, RVP delivered at electromechanically optimized AVD improves symptoms and exercise capacity. (Electromechanically Optimized Right Ventricular Pacing in Obstructive Hypertrophic Cardiomyopathy [EMORI-HCM], NCT05257772).

Background: Persistent symptoms (eg, heart palpitations, lightheadedness, fatigue) despite resolution of acute COVID-19 infection is termed "long COVID syndrome" or simply "long COVID." Long COVID is believed to be associated with autonomic dysfunction, but the nature and severity of any autonomic disturbances are not well understood.

Objectives: This study sought to compare autonomic function measures in patients with long COVID, control subjects, and individuals with pure autonomic failure.

Methods: Patients referred for autonomic testing were classified into 3 groups: long COVID (acute COVID-19 infection ≥12 weeks before testing), control subjects (COVID-19 negative, normal autonomic tests), and pure autonomic failure (COVID-19 negative, abnormal autonomic testing). Heart rate and blood pressure were recorded during active standing, Valsalva maneuver, respiratory sinus arrhythmia, and tilt-table testing.

Results: Compared with control subjects, patients with long COVID exhibited both a greater heart rate increase and blood pressure drop with active standing and tilt-table testing (all P < 0.05). They also had lower Valsalva ratios and respiratory sinus arrhythmia values than did control subjects (both P < 0.05). Compared with pure autonomic failure patients, patients with long COVID had a greater heart rate increase but a lower drop in blood pressure with active standing and tilt-table testing and lesser respiratory sinus arrhythmia values and Valsalva ratios (all P < 0.001). After age and sex adjustment, autonomic dysfunction measures in patients with long COVID were comparable with those in the pure autonomic failure group. Further, autonomic testing abnormalities were observed in patients referred up to 40 months after infection.

Conclusions: When adjusted for age and sex, patients with long COVID may demonstrate persistent autonomic dysfunction that is similar to patients with pure autonomic failure.