RESUMO
OBJECTIVES: To investigate if the effect of cardiac computed tomography (CT) vs. invasive coronary angiography (ICA) on cardiovascular events differs based on smoking status. MATERIALS AND METHODS: This pre-specified subgroup analysis of the pragmatic, prospective, multicentre, randomised DISCHARGE trial (NCT02400229) involved 3561 patients with suspected coronary artery disease (CAD). The primary endpoint was major adverse cardiovascular events (MACE: cardiovascular death, non-fatal myocardial infarction, or stroke). Secondary endpoints included an expanded MACE composite (MACE, transient ischaemic attack, or major procedure-related complications). RESULTS: Of 3445 randomised patients with smoking data (mean age 59.1 years + / - 9.7, 1151 men), at 3.5-year follow-up, the effect of CT vs. ICA on MACE was consistent across smoking groups (p for interaction = 0.98). The percutaneous coronary intervention rate was significantly lower with a CT-first strategy in smokers and former smokers (p = 0.01 for both). A CT-first strategy reduced the hazard of major procedure-related complications (HR: 0.21, 95% CI: 0.03, 0.81; p = 0.045) across smoking groups. In current smokers, the expanded MACE composite was lower in the CT- compared to the ICA-first strategy (2.3% (8) vs 6.0% (18), HR: 0.38; 95% CI: 0.17, 0.88). The rate of non-obstructive CAD was significantly higher in all three smoking groups in the CT-first strategy. CONCLUSION: For patients with stable chest pain referred for ICA, the clinical outcomes of CT were consistent across smoking status. The CT-first approach led to a higher detection rate of non-obstructive CAD and fewer major procedure-related complications in smokers. CLINICAL RELEVANCE STATEMENT: This pre-specified sub-analysis of the DISCHARGE trial confirms that a CT-first strategy in patients with stable chest pain referred for invasive coronary angiography with an intermediate pre-test probability of coronary artery disease is as effective as and safer than invasive coronary angiography, irrespective of smoking status. TRIAL REGISTRATION: ClinicalTrials.gov NCT02400229. KEY POINTS: ⢠No randomised studies have assessed smoking status on CT effectiveness in symptomatic patients referred for invasive coronary angiography. ⢠A CT-first strategy results in comparable adverse events, fewer complications, and increased coronary artery disease detection, irrespective of smoking status. ⢠A CT-first strategy is safe and effective for stable chest pain patients with intermediate pre-test probability for CAD, including never smokers.
RESUMO
The left atrial appendage (LAA) has a key role in the embolic complications of atrial fibrillation (AF). It has been studied extensively, from recent interest in the thrombotic implications of various LAA morphologies to LAA occlusion and ablation. We collected eleven post-mortem LAA samples for visual analysis, two were not included due to poor sample quality. On examination of the nine remaining samples, several common patterns of pectinate muscle orientation were noted. The LAA samples were noted to have a smooth circumferential neck of muscular tissue giving rise to a dominant singular smooth trunk of papillary muscle in 6 cases and two trunks in 3 cases. These trunks were either shallow (5 samples) or more muscular and raised (4 samples). Shallow trunks tended to be wider than the raised trunks and may even be circumferential (2 samples). The main trunk arborized to give off papillary muscle branches down to third or fourth order branches. The samples were visually assessed for the percentage of smooth papillary muscle versus non-papillary recesses and were found to have ≤50% smooth muscle in 3 samples, 50-75% in 3 samples and >75% in 3 samples. We performed histological analysis of further LAA samples collected during cardiac surgery in a parallel study. We identified a distinct pattern of myocyte orientation from the neck, mid-section and apical section of the LAA demonstrating arborization of myocyte fibers with minimal communication in distal segments of the LAA. We feel that this information may help understanding of the issues surrounding LAA ablation strategies.