Lenient rate control versus strict rate control for atrial fibrillation: a protocol for the Danish Atrial Fibrillation (DanAF) randomised clinical trial.

INTRODUCTION: Atrial fibrillation is the most common heart arrhythmia with a prevalence of approximately 2% in the western world. Atrial fibrillation is associated with an increased risk of death and morbidity. In many patients, a rate control strategy is recommended. The optimal heart rate target is disputed despite the results of the the RAte Control Efficacy in permanent atrial fibrillation: a comparison between lenient vs strict rate control II (RACE II) trial.Our primary objective will be to investigate the effect of lenient rate control strategy (<110 beats per minute (bpm) at rest) compared with strict rate control strategy (<80 bpm at rest) on quality of life in patients with persistent or permanent atrial fibrillation. METHODS AND ANALYSIS: We plan a two-group, superiority randomised clinical trial. 350 outpatients with persistent or permanent atrial fibrillation will be recruited from four hospitals, across three regions in Denmark. Participants will be randomised 1:1 to a lenient medical rate control strategy (<110 bpm at rest) or a strict medical rate control strategy (<80 bpm at rest). The recruitment phase is planned to be 2 years with 3 years of follow-up. Recruitment is expected to start in January 2021. The primary outcome will be quality of life using the Short Form-36 (SF-36) questionnaire (physical component score). Secondary outcomes will be days alive outside hospital, symptom control using the Atrial Fibrillation Effect on Quality of Life, quality of life using the SF-36 questionnaire (mental component score) and serious adverse events. The primary assessment time point for all outcomes will be 1 year after randomisation. ETHICS AND DISSEMINATION: Ethics approval was obtained through the ethics committee in Region Zealand. The design and findings will be published in peer-reviewed journals as well as be made available on ClinicalTrials.gov. TRIAL REGISTRATION NUMBER: NCT04542785.

Diagnostic Value of the Updated Diamond and Forrester Score to Predict Coronary Artery Disease in Patients with Acute-Onset Chest Pain.

OBJECTIVES: In the recently updated clinical guidelines from the European Society of Cardiology on the management of stable coronary artery disease (CAD), the updated Diamond Forrester score has been included as a pretest probability (PTP) score to select patients for further diagnostic testing. We investigated the validity of the new guidelines in a population of patients with acute-onset chest pain. METHODS: We examined 527 consecutive patients with either an exercise-ECG stress test or single-photon emission computed tomography, and subsequently coronary computed tomography angiography (CCTA). We compared the diagnostic accuracy of PTP and stress testing assessed by the area under the receiver operating characteristic curve (AUC) to identify significant CAD, defined as at least 1 coronary artery branch with >70% diameter stenosis identified by CCTA. RESULTS: The diagnostic accuracy of PTP was significantly higher than the stress test (AUC 0.80 vs. 0.69; p = 0.009), but the diagnostic accuracy of the combination of PTP and a stress test did not significantly increase when compared to PTP alone (AUC 0.86 vs. 0.80; p = 0.06). CONCLUSIONS: PTP using the updated Diamond and Forrester Score is a very useful tool in risk-stratifying patients with acute-onset chest pain at a low-to-intermediate risk of having CAD. Adding a stress test to PTP does not appear to offer significant diagnostic benefit.

Transmural myocardial perfusion gradients in relation to coronary artery stenoses severity assessed by cardiac multidetector computed tomography.

To assess the relationship between epicardial coronary artery stenosis severity and the corresponding regional transmural perfusion at rest and during adenosine stress, using multidetector computed tomography (MDCT). We evaluated the relationship between the severity of coronary artery diameter stenosis assessed by MDCT angiography and semi-quantitative myocardial MDCT perfusion in 200 symptomatic patients. The perfusion index (PI = mean myocardial attenuation density/mean left ventricular lumen attenuation density) at rest and during adenosine stress, the myocardial perfusion reserve (MPR = stress - PI/rest - PI), and the transmural perfusion ratio (TPR = subendocardium/subepicardium) were calculated. A coronary artery stenosis ≥50 % was present in 49 patients (25 %). Rest-PI and rest-TPR values were similar in patients with and without a coronary artery stenosis ≥50 %, whereas stress-PI, stress-TPR and MPR were significantly reduced in patients with a stenosis ≥50 % (p < 0.001, p < 0.0001 and p = 0.02, respectively). Subendocardial PI was significantly higher than subepicardial PI at rest and during stress for patients without a significant stenosis, whereas this difference was blurred during stress in patients with ≥50 % stenosis. In a broad spectrum of stenosis severity groups, TPR at rest remained unchanged until the group of patients with total occlusions, whereas TPR during stress decreased progressively when a threshold of 50 % was superseded. In this study we establish the relationship between semi-quantitative perfusion measurements by MDCT and severity of coronary artery stenoses and find the transmural myocardial perfusion ratio to be a potential strong functional index of the hemodynamic significance of coronary artery atherosclerotic lesions.

Cardiac computed tomography guided treatment strategy in patients with recent acute-onset chest pain: results from the randomised, controlled trial: CArdiac cT in the treatment of acute CHest pain (CATCH).

OBJECTIVES: In patients admitted on suspicion of acute coronary syndrome, with normal electrocardiogram and troponines, we evaluated the clinical impact of a Coronary CT angiography (CCTA)-strategy on referral rate for invasive coronary angiography (ICA), detection of significant coronary stenoses (positive predictive value [PPV]) and subsequent revascularisations, as compared to a function-based strategy (standard care). Secondarily we assessed intermediate term clinical events. METHODS AND RESULTS: We randomised 600 patients to a CCTA-guided strategy (299 patients) or standard care (301 patients). In the CCTA-guided group referral for ICA required a coronary stenosis >70% or >50% in the left main, and for intermediate stenoses (50-70%), a stress test was used. A significant stenosis on ICA was defined as a stenosis ≥70% or reduced FFR ≤0.75 in intermediate stenoses (50-70%). Referral rate for ICA was 17% with CCTA vs. 12% with standard care (p=0.1). ICA confirmed significant coronary artery stenoses in 12% vs. 4% (p=0.001), and 10% vs. 4% were subsequently revascularised (p=0.005). PPV for the detection of significant stenoses was 71% with CCTA vs 36% with standard care (p=0.001). Clinical events (cardiac death, myocardial infarction, unstable angina pectoris, revascularisation and readmission for chest pain), during 120 days of follow-up, were recorded in 8 patients (3%) in the CCTA-guided group vs. 15 patients (5%) in the standard care group (p=0.1). CONCLUSION: In patients with recent acute-onset chest pain, a CCTA-guided diagnostic strategy improves PPV for the detection of significant coronary stenoses, and increases the frequency of revascularisations, when compared to a conventional functional approach.