Are drug-eluting stents safe and effective in the long term?

The introduction of drug-eluting stents in 2002 revolutionized interventional cardiology by minimizing restenosis. Reports of increased late stent thrombosis with these stents compared with bare metal stents, probably due to delayed endothelialization, emerged late in 2006. These studies contained serious methodological flaws, however. Subsequent meta-analyses clearly showed only a small incremental risk of late stent thrombosis across all patient groups. Importantly, a significant and sustained benefit of drug-eluting stents due to reduced restenosis and thus repeat revascularization was also shown. Several 'real-world' registries have confirmed these results and suggested that the use of these stents in more complex situations is not associated with adverse outcomes. Stent thrombosis is a multifactorial problem, in which the stent is only one element. Further research is required to determine optimal procedural technique and antiplatelet regimens. Drug-eluting stents are safe and effective in the long-term, though intensive research continues into ways to reduce the risk of stent thrombosis in the next generation.     

Are beta-blockers effective in elderly patients who undergo coronary revascularization after acute myocardial infarction?

BACKGROUND: Although randomized clinical trials have demonstrated that beta-blocker therapy is effective in reducing mortality after acute myocardial infarction (AMI), many of these studies excluded patients who undergo coronary revascularization. However, the clinical practice guidelines established by the American College of Cardiology and the American Heart Association recommend that beta-blocker therapy be considered for patients who underwent successful revascularization after AMI. METHODS: Using data from the Cooperative Cardiovascular Project, we compared the initiation of beta-blocker therapy at discharge in patients aged 65 years or older who underwent coronary artery bypass surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA) during their hospitalization for AMI with that of patients who did not undergo revascularization. We then examined whether beta-blocker therapy was associated with lower 1-year mortality between revascularized and nonrevascularized groups. RESULTS: After excluding patients with contraindications to beta-blocker therapy, 84 457 patients remained in the study sample. Of these, 8482 patients underwent CABG, and 13 997 patients underwent PTCA. After adjusting for demographic and clinical factors, we found that these patients were less likely to initiate beta-blocker therapy after CABG (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.41-0.47) or PTCA (OR, 0.89; 95% CI, 0.85-0.93) relative to the nonrevascularized group. After adjusting for potential confounders, beta-blockers were significantly associated with lower 1-year mortality in patients who underwent CABG (hazard ratio [HR], 0.70; 95% CI, 0.55-0.89) or PTCA (HR, 0.86; 95% CI, 0.74-1.00), similar to that of the non-revascularized group (HR, 0.83; 95% CI, 0.80-0.87). CONCLUSIONS: Therapy after AMI with beta-blockers appears to be as effective in reducing 1-year mortality for elderly patients who have undergone CABG or PTCA as for a nonrevascularized group. Our findings suggest that routine use of beta-blockers should be considered for patients who undergo revascularization after AMI.     

Do collaterals affect heart rate variability in patients with acute myocardial infarction?

BACKGROUND: The protective effects and the prognostic importance of collaterals during and after acute myocardial infarction (MI) are under debate and heart rate variability (HRV) is a strong predictor of risk of mortality and arrhythmic events after acute MI. We aimed to examine the effects of collateral circulation on HRV in the early period after acute MI. METHODS: Sixty-four patients admitted to our clinics who were diagnosed with acute anterior MI and underwent thrombolytic therapy were enrolled in this study. We applied 24 h Holter monitoring for HRV analysis to all patients and compared the patients with and without collaterals to the infarct-related artery. RESULTS: Mean heart rate, low frequency (LF) (day, night and 24 h) and LF/high frequency (HF) (day, night and 24 h) were higher, SD of all NN intervals (SDNN), root mean square of successive differences (RMSSD), number of NN intervals that differed by more than 50 ms from the adjacent interval divided by the total number of all NN intervals (PNN50) and HF night values were lower in patients without collaterals than in those with collaterals. SDNN was negatively correlated with left anterior descending coronary artery (LAD) stenosis, ventricle score indices and left ventricular ejection fraction (LVEF); LF/HF ratio was positively correlated with ventricle score indices and negatively correlated with LVEF and Thrombolysis in Myocardial Infarction flow grade. Linear regression analysis showed that ventricle score index and coronary collaterals affect HRV and LAD stenosis, ventricle score, LVEF and coronary collaterals affect LF/HF ratio. A SDNN <80 ms increased the development of ventricular arrhythmias in the early period by 4.7 fold, a LF/HF ratio >2.7 increased it by 9.8 fold and a LVEF <35% increased it by 12.8 fold, whereas the presence of well-developed collaterals decreased the arrhythmia development by 2.5 fold. CONCLUSIONS: The collaterals to the infarct-related artery have great impact on HRV, autonomic nervous system activity and the development of ventricular arrhythmias in patients with acute anterior MI. Our results suggest a protective role of collaterals on myocardial electrophysiology in the early period after acute MI.     

Are we underestimating the full potential of early thrombolytic treatment in patients with acute myocardial infarction?

Use of the Boersma curve in order to describe the beneficial effect of thrombolytic treatment at different treatment delays seems questionable, because the curve may underestimate the favourable prognostic effects of early thrombolysis in patients with acute myocardial infarction     

Why do acute myocardial infarction patients not call an ambulance? An interview with patients presenting to hospital with acute myocardial infarction symptoms

BACKGROUND: Studies from overseas indicate that patients with acute myocardial infarction (AMI) symptoms often fail to use the emergency services as recommended, thereby depriving themselves from life-saving treatment in case of cardiac arrest and delaying the time to myocardial reperfusion in the presence of a coronary occlusion. AIMS: To compare patients brought in by ambulance to those not brought in by ambulance and to question why some patients do not use the emergency services when presenting to hospital with AMI symptoms. METHODS: Prospective interview and follow up of consecutive patients presenting with AMI symptoms to the emergency department of a tertiary hospital in a metropolitan area within a 1-month period. RESULTS: Of the 215 patients presenting to the emergency department, 113 (53%) arrived by private transportation. Sixty (53%) of these felt their symptoms did not warrant calling the ambulance, 17 (15%) had first consulted their general practitioner. The private transport group accounted for 28% of documented AMI. CONCLUSIONS: A large proportion of patients with AMI symptoms refrain from calling the emergency services because they do not consider themselves critically ill. Education programmes appear to be warranted because more appropriate use of emergency services will save lives.     

Drug-eluting stents and acute myocardial infarction:A lethal combination or friends?

Primary percutaneous coronary intervention is the preferred reperfusion strategy for patients presenting with ST-segment elevation myocardial infarction(STEMI). First generation drug-eluting stents(DES),(sirolimus drug-eluting stents and paclitaxel drug-eluting stents), reduce the risk of restenosis and target vessel revascularization compared to bare metal stents. However, stent thrombosis emerged as a major safety concern with first generation DES. In response to these safety issues, second generation DES were developed with different drugs, improved stent platforms and more biocompatible durable or bioabsorbable polymeric coating. This article presents an overview of safety and efficacy of the first and second generation DES in STEMI.     

Is silent myocardial infarction more common in women with type 2 diabetes than in men?

ObjectiveOur aim was to determine if silent myocardial infarction (MI) is more common in women with type 2 diabetes than in men. Our secondary aim was to examine the relationships between silent MI and risk factors for cardiovascular disease.Research design and methodsThe Action to Control Cardiovascular Risk in Diabetes (ACCORD) database was used to determine if women had more silent MI on baseline electrocardiograms (ECGs) than did men with a similar unremarkable cardiovascular history. MI was diagnosed using ECG analysis according to the Minnesota code. Multivariable logistic regression analysis was used to compare demographic and clinical associations. Interactive effects of risk factors by gender were tested using a forward selection algorithm.ResultsMen were found to have a higher prevalence of silent MI on baseline ECGs than women (6% vs 4%, P = .001). Women had lower odds of silent MI than men after adjusting for other risk factors (OR = 0.80, P = .04). Race and ethnicity were significantly associated with silent MI (P = .02), with Asians having the highest and African Americans and Hispanics having lower odds relative to whites.ConclusionsOur main findings provide no evidence that silent MI, as detected by the Minnesota code, was more common in women than in men in the ACCORD cohort. If, as in the general population, the women in ACCORD are found to have a higher heart disease mortality rate than the men, it seems unlikely that failure to recognize clinically silent heart disease in the years before study enrollment could be a major cause.