Cardioprotective Role of Remote Ischemic Periconditioning in Primary Percutaneous Coronary Intervention Enhancement by Opioid Action

ObjectivesWe sought to determine the potential of remote ischemic periconditioning (RIPC), and its combination with morphine, to reduce reperfusion injury in primary percutaneous coronary interventions.BackgroundRemote ischemic post-conditioning is implemented by applying cycles of ischemia and reperfusion on a remote organ, which result in release of circulating factors inducing the effects of post-conditioning on the myocardium.MethodsA total of 96 patients (59 men) were enrolled. The patients were randomized to groups as follows: 33 to each treatment group (Group A: RIPC; Group B: RIPC and morphine) and 30 to the control group (Group C). Measures of efficacy were achievement of full ST-segment resolution (primary), and reduction of ST-segment deviation score and peak troponin I during hospitalization.ResultsA higher proportion of patients in Groups A (73%) and B (82%) achieved full ST-segment resolution after percutaneous coronary intervention, compared with control patients (53%) (p = 0.045). Peak troponin I was lowest in Group B, 103.3 ± 13.3 ng/ml, in comparison to peak levels in Group A, 166.0 ± 28.0 ng/ml, and the control group, 255.5 ± 35.5 ng/ml (p = 0.0006). ST-segment deviation resolution was 87.3 ± 2.7% in Group B, compared with 69.9 ± 5.1% in Group A and 53.2 ± 6.4% in the control group (p = 0.00002). In paired comparisons between groups, Group B did better than the control group in terms of both ST-segment reduction (p = 0.0001) and peak troponin I (p = 0.004), whereas Group A differences from the control group did not achieve statistical significance (p = 0.054 and p = 0.062, respectively).ConclusionsThese findings demonstrate a cardioprotective effect of RIPC and morphine during primary percutaneous coronary intervention for the prevention of reperfusion injury. This is in agreement with observations that the beneficial effect of RIPC is inhibited by the opioid receptor blocker naloxone

Relation of Ventricular Tachycardia/Fibrillation to Beta-Blocker Dose Maximization Guided by Pacing Mode Analysis in. Nonpacemaker-Dependent Patients With Implantable Cardioverter-Defibrillator

We hypothesized that uptitration of beta blockade and adjustment of pacing parameters to achieve a prevalence of single chamber atrial inhibited rate-responsive (AAIR) pacing in patients with dual-chamber implantable cardioverter-defibrillators (ICDs) would result in maximization of beta-blocker dosage and thus decrease appropriate ICD therapies. We included patients with ischemic or dilated cardiomyopathy and implanted ICDs without contraindications to beta blockers and atrioventricular conduction disturbances. Two 6-month periods were compared: clinically guided phase (pacing function set at back-up dual-chamber rate-responsive pacing mode at a lower rate of about 40 beats/min) and pacing-guided phase, during which beta-blocker dosage was titrated with a target of achieving >90% AAIR pacing (lower rate 60 beats/min). Sixty-one patients (64.2 +/- 8.3 years old) were included. During the pacing-guided phase the target of >= 90% AAIR pacing was achieved in 80.3% of patients. Mean metoprolol dose during the clinically guided phase was 96.7 +/- 29.4 versus 127.0 +/- 39.6 mg/day in the pacing-guided phase (p <0.001). Appropriate ICD therapies were recorded in 35 patients (57.4%) during the clinically guided phase versus 20 (32.8%) during the pacing-guided phase (p <0.001; 1.15 and 0.48 appropriate ICD therapies per patient, respectively, p <0.001). In multivariate analysis, AAIR pacing and beta-blocker dose were inversely related to appropriate ICD therapies. In conclusion, a pacing-guided approach for maximizing beta-blocker doses guided by maximizing AAIR pacing in patients with ICDs may be beneficial compared to the conventional strategy. This pacing-guided approach led to higher daily beta-blocker doses, which were correlated to fewer appropriate ICD therapies. (C) 2011 Elsevier Inc. All rights reserved. (Am J Cardiol 2011; 107:1812-1817

Comparison of Muscle Functional Electrical Stimulation to Conventional Bicycle Exercise on Endothelium and Functional Status Indices in Patients With Heart Failure

The aim of this prospective, open-label, cohort study was to compare the effect of muscle functional electrical stimulation (FES) on endothelial function to that of conventional bicycle training. Eligible patients were those with New York Heart Association class II or III heart failure symptoms and ejection fractions <= 0.35. Two physical conditioning programs were delivered: FES of the muscles of the lower limbs and bicycle training, each lasting for 6 weeks, with a 6-week washout period between them. Brachial artery flow-mediated dilation (FMD) and other parameters were assessed before and after FES and the bicycle training program. FES resulted in a significant improvement in FMD, which increased from 5.9 +/- 0.5% to 7.7. +/- 0.5% (95% confidence interval for the difference 1.5% to 2.3%, p <0.001). Bicycle training also resulted in a substantial improvement of endothelial function. FMD increased from 6.2 +/- 0.4% to 9.2 +/- 0.4% (95% confidence interval for the difference 2.5% to 3.5%, p <0.001). FES was associated with a 41% relative increase in FMD, compared to 57% with bicycle exercise (95% confidence interval for the difference between the relative changes 1.2% to 30.5%, p = 0.034). This resulted in attaining a significantly higher FMD value after bicycle training compared to FES (9.2 +/- 0.4% vs 7.7 +/- 0.5%, p <0.001). In conclusion, the effect of muscle FES in patients with heart failure on endothelial function, although not equivalent to that of conventional exercise, is substantial. Muscle FES protocols may prove very useful in the treatment of patients with heart failure who cannot or will not adhere to conventional exercise programs. (C) 2010 Elsevier Inc. All rights reserved. (Am J Cardiol 2010;106:1621-1625

Estimation of atrial fibrillation recency of onset and safety of cardioversion using NTproBNP levels in patients with unknown time of onset

Objective As shown previously in patients with new-onset atrial fibrillation (AF) without symptoms or signs of heart failure, N-terminal pro-brain natriuretic peptide (NTproBNP) increases rapidly, reaching a maximum within 24-36 h, and then decreases even if AF persists. A study was undertaken to use NTproBNP measurements in patients with AF of unknown time of onset to identify patients with presumed recent onset of the arrhythmia. Design Two-group open cross-sectional study. Setting Hospitalised patients in cardiology departments of four hospitals. Patients Patients presenting with AF of unknown onset and no signs or symptoms of heart failure were separated into two groups: group A with NTproBNP above the cut-off level and group B with a low NTproBNP level. Interventions No therapeutic intervention. All patients underwent transoesophageal echocardiography (TEE). Main outcome measures Presence of left atrial thrombus on TEE. Results In group A (N=43) only two patients (4.7%) were found to have an atrial thrombus on TEE (negative predictive value of raised NTproBNP levels 95.3%) compared with 13 of 43 patients in group B (30.2%; p=0.002). Patients with a higher CHA(2)DS(2)VASc score (p=0.002) and a larger left atrium (p < 0.001) were more likely to have an atrial thrombus. In the multivariate analysis, NTproBNP below the cut-off level was the most powerful predictor of the presence of thrombus (OR 25.0; p=0.016). Conclusion The reported strong correlation between raised NTproBNP levels and the absence of atrial thrombi on TEE suggests that the short-term increase in NTproBNP levels after AF onset might be used to assess the age of the arrhythmia and thus the safety of cardioversion in patients with AF of unknown onset and no heart failure