Daily Cardiology Research Analysis

BACKGROUND: Nitrates remain a key drug class in the management of angina pectoris. However, their effect on coronary blood flow has never been convincingly demonstrated in humans. OBJECTIVES: The aim of this study was to assess the impact of sublingual nitroglycerin (NTG) on absolute coronary blood flow, coronary resistance, and left ventricular work. METHODS: A randomized, double-blind, placebo-controlled, mechanistic study was conducted. Forty patients with suspected angina underwent cardiac catheterization and randomization to sublingual NTG (n = 20) or a placebo control (n = 20). Using continuous intracoronary thermodilution, baseline absolute coronary blood flow (the primary outcome) and a range of other hemodynamic parameters were measured. Following delivery of the sublingual intervention, repeat measurements were made after 5 and 10 minutes. Between-group differences were analyzed using analysis of covariance. RESULTS: Sublingual NTG resulted in a significant decrease in mean left ventricular end-diastolic pressure of 38.1% (95% CI: 21.8%-54.4%) (estimated mean difference -5.4 mm Hg; 95% CI: -7.8 to -3.1 mm Hg; P < 0.001), along with significant decreases in aortic pressure of 8.5% (95% CI: 5.3%-11.7%) (estimated mean difference -8.6 mm Hg; 95% CI: -12.2% to -5.1%; P < 0.001) and distal coronary pressure of 7.4% (95% CI: 3.7%-11.1%) (estimated mean difference -7.1 mm Hg; 95% CI: -10.6 to -3.7 mm Hg; P < 0.001) after 10 minutes. Myocardial work also decreased by 21.1% (95% CI: 15.4%-26.9%) (estimated mean difference -8.9 mm Hg · s; 95% CI: -11.6 to -6.2 mm Hg · s; P < 0.001). Despite inducing a significant increase in vessel volume, NTG resulted in a significant increase in microvascular resistance of 8.0% (95% CI: 1.1%-14.9%) (estimated mean difference 121.5 Wood units; 95% CI: 15.3-227.8 Wood units; P = 0.026) and a corresponding decrease in absolute coronary blood flow of 13.3% (95% CI: 6.4%-20.2%) (estimated mean difference -8.7 mL/min; 95% CI: -13.4 to -3.9 mL/min; P = 0.001). CONCLUSIONS: Sublingual NTG induced a significant decrease in left ventricular preload and afterload, resulting in a marked decrease in myocardial work. This was associated with a significant and adaptive decrease in absolute coronary blood flow.

Atrial fibrillation (AF) increases the risk of stroke and heart failure, yet accurate quantification of AF burden in daily life remains difficult. Although smartwatch photoplethysmography (PPG) supports continuous monitoring, complex rhythms and signal noise can impair burden estimation. We developed an AI-enhanced dual-modal framework that combines continuous watch-based PPG (W-PPG) with intermittent single-lead watch-based ECG (W-ECG). A hybrid convolutional neural network-long short-term memory model uses high-fidelity W-ECG segments as dynamic anchors to correct long-term W-PPG classifications. In this prospective validation study, 1,054 patients with AF undergoing catheter ablation (mean age, 62.1 years) were evaluated against patch-based ECG as the reference standard. After ECG-based correction, the system achieved 98.60% sensitivity and 99.27% specificity. The mean absolute percentage error of AF burden decreased by 23.4%, from 1.11% to 0.85%, while the Pearson correlation remained 0.9988. This dual-modal approach offers a scalable and clinically practical solution for long-term AF monitoring, improving burden estimation beyond PPG-only devices without requiring continuous multi-lead ECG. It may support personalized AF management and large-scale cardiovascular screening in real-world settings. (NCT06552468).

BACKGROUND: There is a growing consensus that screening for subclinical preheart failure (HF) may reduce the burden of symptomatic HF by allowing for timely preventive interventions. However, validated screening algorithms are currently lacking. The aim of this study was to evaluate a fully mobile telemedically supervised cardiac magnetic resonance, as a simple standardized, and ubiquitously applicable screening algorithm for subclinical pre-HF in rural and underresourced regions. METHODS: HERZCHECK was a cross-sectional cohort study conducted at 12 sites across rural and underresourced regions of Germany. Asymptomatic participants (40-69 years) with ≥1 cardiovascular risk factor-obesity, smoking, arterial hypertension, diabetes, hypercholesterolemia, or chronic kidney disease-were enrolled and underwent telemedically supervised contrast-free short cardiac magnetic resonance in mobile screening units. Subclinical pre-HF was diagnosed using a predefined cutoff of global longitudinal strain ≥-15%. A matched and entropy-balanced control cohort constructed from claims data was used to determine the time difference between detection of subclinical pre-HF in HERZCHECK and the first symptom-based diagnosis of HF within the standard of care. RESULTS: Between June 2021 and April 2023, 4666 participants were enrolled in the study, of which 4509 participants were included in the final analysis. The prevalence of subclinical pre-HF in the studied at-risk population was 22.7% (95% CI, 21.5%-23.9%). Global longitudinal strain-based screening identified subclinical pre-HF 6.7 years before the average onset of symptomatic HF within the standard of care (n=8420). CONCLUSIONS: Subclinical pre-HF affects approximately one-fourth of the at-risk population in rural and underresourced regions. The HERZCHECK approach identifies patients suitable for targeted preventive interventions ≈7 years earlier than the standard of care. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT05122793.