Diagnostic Performance of Frequency-Domain Optical Coherence Tomography to Predict Functionally Significant Left Main Coronary Artery Stenosis.

AIMS: The aim of this study was to assess the safety and diagnostic efficacy of frequency-domain optical coherence tomography (FD-OCT) in identifying functional severity of the left main coronary artery (LM) stenosis determined by fractional flow reserve (FFR). METHODS AND RESULTS: 101 patients with LM lesion (20-70% diameter stenosis angiographically) underwent FFR measurement and FD-OCT imaging of the LM. The following parameters were measured by FD-OCT in the LM: reference lumen area (RLA), reference lumen diameter (RLD), minimum lumen area (MLA), minimum lumen diameter (MLD), % lumen area stenosis, and % diameter stenosis. The LM lesions were analyzable by FD-OCT in 88/101 (87.1%) patients. FFR at maximum hyperemia was ≤0.80 in 39/88 (44.3%) patients. FFR values were correlated significantly with FD-OCT-derived LM lumen parameters. An MLA cutoff value of 5.38 mm2 had the highest sensitivity and specificity of 82% and 81%, respectively, followed by an MLD of 2.43 mm (sensitivity 77%, specificity 72%) and AS of 60% (sensitivity 72%, specificity 72%) for predicting FFR <0.80. CONCLUSIONS: FD-OCT is a safe and feasible imaging technique for the assessment of LM stenosis. An FD-OCT-derived MLA of ≤5.38 mm2 strongly predicts the functional severity of an LM lesion.

Biomarkers of Myocardial Injury and Inflammation after Permanent Pacemaker Implantation: The Lead Fixation Type Effect.

BACKGROUND: Permanent pacemaker implantation is accompanied by minor myocardial damage, indicated by elevated serum levels of cardiac biomarkers. Aim of this prospective study was to comparably investigate the lead fixation type effect on the extent of myocardial injury and inflammation following pacemaker implantation, and to assess the possible clinical implications. METHODS: Cardiac troponin I (cTnI) and C-reactive protein (CRP) were measured at baseline, 6 and 24h after implantation in 101 patients, categorized into the active and passive lead fixation group. Patients were followed up for clinical adverse events or abnormal pacing parameters at 24h, 7 and 30 days post-procedure. RESULTS: cTnI increased at 6h post-procedure (p<0.05) in 23.8% of patients, and returned to baseline after 24h. The passive group demonstrated significantly higher cTnI at 6h compared to the active group (p=0.006). CRP increased significantly at 6h, and maintained an upward trend after 24h (p<0.01) in both groups. The active group demonstrated significantly higher CRP at 6h compared to the passive group. We did not identify an association of positive biomarkers with adverse events. CONCLUSION: cTnI and CRP can increase early after permanent pacemaker implantation, indicating mechanical myocardial injury and inflammation. The extent of these biomarkers elevation depends on the lead fixation type, and is not related to worse short-term prognosis.