Effect of Angiotensin Receptor Blocker Dose in Myocardial Infarction With Preserved Left Ventricular Systolic Function.

ABSTRACT: There have been few studies of angiotensin receptor blocker (ARB) dose in myocardial infarction (MI) with preserved left ventricular (LV) systolic function. We evaluated the association of ARB dose with clinical outcomes after MI with preserved LV systolic function. We used MI multicenter registry. Six months after discharge, the ARB dose was indexed to the target ARB doses used in randomized clinical trials and grouped as >0%-25% (n = 2333), >25% of the target dose (n = 1204), and no ARB (n = 1263). The primary outcome was the composite of cardiac death or MI. Univariate analysis showed that mortality of those with any ARB dose was lower than those without ARB therapy. After multivariable adjustment, patients receiving >25% of target dose had a similar risk of cardiac death or MI compared with those receiving ≤25% or no ARB [hazard ratio (HR) 1.05, 95% confidence interval (CI) 0.83-1.33; HR 0.94, 95% CI 0.82-1.08, respectively]. Propensity score analysis also demonstrated that patients with >25% dose had no difference in primary endpoint compared with those ≤25% dose or the no ARB group (HR 1.03, 95% CI 0.79-1.33; HR 0.86, 95% CI 0.64-1.14, respectively). The present study demonstrates that patients treated with >25% of target ARB dose do not have better clinical outcomes than those treated with ≤25% of target ARB dose or those with no ARB dose in MI patients with preserved LV systolic function.

Renin-angiotensin system blockade reduces cardiovascular events in nonheart failure, stable patients with prior coronary intervention.

BACKGROUND: The effects of renin-angiotensin system (RAS) blockade on the clinical outcome in patients with stable coronary artery disease (SCAD) are conflicting. We evaluated the long-term effects of RAS blockers (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker) on the clinical outcomes in patients with SCAD without heart failure (HF) who underwent percutaneous coronary intervention (PCI) with drug-eluting stent using a large-scale, multicenter, prospective cohort registry. METHODS: A total of 5722 patients with SCAD were enrolled and divided into two groups according to the use of RAS blockers after PCI: RAS blocker group included 4070 patients and no RAS blocker group included 1652 patients. Exclusion criteria were left ventricular ejection fraction less than 50% and the history of HF or myocardial infarction. A major adverse cardiovascular event (MACE) was defined as a composite of cardiovascular death, nonfatal myocardial infarction, and stroke. RESULTS: During a median follow-up of 29.7 months, RAS blockers were associated with a significant reduction in the risk of MACE [adjusted hazard ratio (HR): 0.781; 95% confidence interval (CI): 0.626-0.975; P=0.015] and all-cause death (adjusted HR: 0.788; 95% CI: 0.627-0.990; P=0.041) but did not affect the risk of coronary revascularization. In the propensity score matched cohort, overall findings were consistent (MACE: adjusted HR: 0.679; 95% CI: 0.514-0.897; P=0.006; all-cause death: adjusted HR: 0.723; 95% CI: 0.548-0.954; P=0.022), and the benefit of RAS blockade was maintained in all predefined subgroups. CONCLUSION: This study demonstrated that RAS blockers were effective preventive therapies for reducing long-term cardiovascular events in patients with SCAD without HF who underwent PCI.

Comparison of magnetic navigation system and conventional method in catheter ablation of atrial fibrillation: is magnetic navigation system is more effective and safer than conventional method?

BACKGROUND AND OBJECTIVES: Although there have been so many reports of catheter ablation of atrial fibrillation (AF) with magnetic navigation system (MNS), it is not necessarily obvious that MNS is more effective than conventional ablation. We performed AF ablation with MNS and compared the clinical outcomes and radiofrequency ablation parameters with those of conventional ablation. SUBJECTS AND METHODS: One hundred eleven consecutive patients (conventional group, n=70 vs. MNS group, n=41) undergoing catheter ablation of AF were enrolled. We compared and analyzed the procedural parameters, namely fluoroscopic time, procedural time, acute procedural success and 3 months success rate of both groups. RESULTS: The MNS group was associated with slightly larger left atrial size (43.7±6.3 mm vs. 41.2±6.3 mm, p=0.04), significantly longer total procedure time (352±50 minutes vs. 283±75 minutes, p<0.0001), and shorter total fluoroscopic time (99±28 minutes vs. 238±45 minutes, p<0.0001) than the conventional group. The MNS and conventional group did not differ with respect to acute procedural success, AF recurrence, atrial flutter/atrial tachycardia recurrence, or total arrhythmia recurrence. While no complications were observed in the MNS group, eight cases of significant pericardial effusion occurred in the conventional group. CONCLUSION: The MNS system seems to be effective and safe in the catheter ablation of AF, particularly in the population of patients with persistent AF and slightly dilated left atria.

Radiofrequency catheter ablation and nerve growth factor concentration in humans.

BACKGROUND: In animal models, expression of nerve growth factor (NGF) is increased after necrotic myocardial injury. Whether radiofrequency (RF) catheter ablation increases NGF expression in humans is unclear. OBJECTIVES: The purpose of this study was to determine NGF concentrations in the aorta, coronary sinus, and peripheral veins before and after RF ablation in patients. METHODS: We sampled blood from aorta and either great cardiac vein (group 1, N = 18) or proximal (group 2, N = 20) coronary sinus before and after RF ablation. In group 3 (N = 21), peripheral venous blood was sampled before and after RF ablation and then up to postoperative day 7. In group 4 (N = 10), we sampled peripheral venous blood during diagnostic electrophysiologic study. The NGF concentration was determined by enzyme-linked immunosorbent assay. Transcardiac NGF concentration was the difference in NGF concentrations between coronary sinus and aorta. RESULTS: There was no change in transcardiac NGF concentrations in groups 1 and 2. In group 3, the NGF level did not change significantly from before the procedure (17.10 +/- 15.80 ng/mL) to immediately after the procedure (14.46 +/- 10.36 ng/mL). However, NGF levels increased significantly to 31.24 +/- 19.82 ng/mL (N = 21, P <.0001) on postoperative day 1, 26.23 +/- 16.89 ng/mL (N = 20, P <.001) on postoperative day 2, and 22.01 +/- 11.35 ng/mL (N = 16, P = .003) on postoperative day 3. NGF concentrations did not change significantly in group 4. CONCLUSION: RF ablation did not result in a detectable increase of transcardiac NGF concentration immediately after the procedure. However, the systemic NGF concentration increased significantly on postoperative days 1 to 3, suggesting that RF ablation resulted in increased NGF expression.