Effect of ambulance 12-lead ECG recording on times to hospital reperfusion in acute myocardial infarction

OBJECTIVE: To review the evidence that recording a prehospital 12-lead electrocardiogram (ECG) reduces time from hospital arrival to initiation of reperfusion therapy for acute myocardial infarction (AMI). DATA SOURCES: Medline search from 1966 to the present (articles in all languages) and examination of bibliographies. STUDY SELECTION: Published studies of prehospital 12-lead ECG recording that included control groups and reported time intervals from hospital arrival to start of reperfusion therapy. DATA EXTRACTION: Eight articles satisfied selection criteria (two randomised controlled trials, four non-randomised interventional studies and two prospective observational studies). DATA SYNTHESIS: Widely varying study methodologies precluded meta-analysis. All studies had methodological problems, but hospital delays were consistently reduced. Such improvements appear to be small in hospitals where delays are already minimal. CONCLUSIONS: Little evidence is available to support routine prehospital 12-lead ECG recording if the median hospital time to reperfusion is already less than 30 minutes. Improvement of in-hospital treatment times may be a better initial strategy than prehospital 12-lead ECG recording, as this will benefit more patients and allow ambulance services to better allocate their available resources.     

Acute myocardial infarction in Fukushima area of Japan

Although acute myocardial infarction (AMI) is the most serious coronary disease, the background of its onset and the mortality are not fully understood, especially in Japan. From June 1999 to May 2005, we mailed an annual questionnaire to eighteen hospitals in which emergency cardiac catheterization and percutaneous coronary intervention (PCI) were available in the Fukushima area of Japan. A total of 1,590 patients were included. The onset time of AMI had two peaks, i.e., from 9:00 AM to 10:00 AM and 9:00 PM to 10:00 PM. As for reperfusion therapy, four groups were analyzed, the non-reperfusion therapy group (Group N, n = 233), thrombolysis alone group (Group T, n = 80), PCI without thrombolysis group (Group P, n = 1106), and PCI with thrombolysis group (Group TP, n = 151). The in-hospital mortality rate was significantly reduced in Group P (8.4%) compared with that in Group N (33.0%, p < 0.01) and Group T (18.8%, p < 0.01). However, the in-hospital mortality in Group P did not differ from that in Group TP (9.9%). The in-hospital mortality was analyzed by the logistic regression analysis among age, arrival time after onset, peak creatine kinase (CK) values, coronary risk factors, reperfusion therapy, PCI, and thrombolysis. There were significant differences in age (P < 0.01), peak CK values (p < 0.01), hypertension (p < 0.05), and diabetes mellitus (p < 0.01). These results suggest that the onset of AMI may be partly related to human biorhythms, and that PCI would be effective in reducing the in-hospital mortality.     

Safety outcomes in meta-analyses of phase 2 vs phase 3 randomized trials: Intracranial hemorrhage in trials of bolus thrombolytic therapy

CONTEXT: Recent studies have reported disagreement between meta-analysis of small trials and subsequent large trials addressing the same question. However, disagreement for uncommon but serious adverse safety outcomes has not been examined. OBJECTIVE: To explore disagreement for serious adverse safety (intracranial hemorrhage [ICH]) and efficacy outcomes between meta-analysis of phase 2 (small) vs meta-analysis of phase 3 (large) randomized controlled trials comparing the efficacy of bolus thrombolytic therapy with infusion for acute myocardial infarction (AMI). DATA SOURCES: Electronic databases (MEDLINE, Cochrane Database of Clinical Trials) between January 1980 and December 1999 using the search terms thrombolysis, thrombolytic therapy, and myocardial infarction; conference proceedings; and reference lists. STUDY SELECTION: Fifteen randomized trials comparing thrombolytic agents administered by bolus injection with standard infusion therapy in patients with AMI. DATA EXTRACTION: Data on ICH, other causes of stroke, total mortality, and reinfarction were independently extracted from each study by 2 observers. DATA SYNTHESIS: Meta-analysis of 9 phase 2 trials (n = 3956) revealed a lower risk of ICH with bolus thrombolytic therapy (odds ratio [OR], 0.53; 95% confidence interval [CI], 0.27-1.01), which was not statistically significant. Meta-analysis of 6 phase 3 trials (n = 62 673) indicated a significant increase in risk of ICH (OR, 1.25; 95% CI, 1.06-1.49). These results were significantly different (P =.01). There was no disagreement for efficacy outcomes. Phase 2 trials included younger and heavier patients with lower baseline blood pressures, and were more often open-label. Subgroup analyses suggested that each of these factors was associated with a lower estimate of risk of ICH with bolus agents. CONCLUSIONS: Our results suggest that when therapeutic interventions are associated with a potential for uncommon but serious adverse safety outcomes, there may be differences between small phase 2 and large phase 3 trials that result in their disagreement for safety but not necessarily efficacy outcomes. Further investigation of the frequency and causes of disagreement between small and large trials for safety outcomes is warranted.     

What are appropriate rates of invasive procedures following acute myocardial infarction? A systematic review

OBJECTIVE: To assess the evidence that higher rates of coronary angiography (CA) and revascularisation (RV) in the subacute phase of acute myocardial infarction (AMI) improve patient outcomes. DATA SOURCES: MEDLINE 1990 - December 1999, Current Contents 1990-1999, Cochrane Library (Issue 4, 1999), HealthSTAR 1990-1999, selected websites and bibliographies of retrieved articles. STUDY SELECTION AND DATA EXTRACTION: Studies selected were (1) randomised trials comparing outcomes of "invasive" versus "conservative" use of CA and RV following AMI; (2) observational studies with formal methods comparing outcomes of high versus low rates of use of these procedures; and (3) clinical practice guidelines (CPGs), expert panel statements and decision analyses which met critical appraisal criteria, and which specified procedural indications. Outcome measures were rates of mortality, re-infarction and limiting or unstable angina. DATA SYNTHESIS: 56 articles were identified; 24 met inclusion criteria. Pooled data from nine RCTs of "invasive" (CA rate 96%; RV rate 66%) versus "conservative" (CA rate 28%; RV rate 19%) strategies showed no significant differences in mortality or re-infarction rates. Pooled results from 12 observational studies showed no mortality differences, but an excess reinfarction rate (8.0% vs 6.4%; P<0.001) in high- versus low-rate populations. Evidence of survival benefit from procedural intervention was strongest for patients with recurrent ischaemia combined with left ventricular dysfunction. CONCLUSIONS: In the subacute phase of AMI, rates of CA and RV in excess of 30% and 20%, respectively, may not confer additional benefit in preventing death or re-infarction. However, variability between studies in design, patient selection, and extent of cross-over from medical to procedural groups, as well as limited data on symptom status, limits generalisability of results.     

老年性急性心肌梗塞临床分析（附97例报告）

目的：研究老年性急性心肌梗塞（AMI）的临床经过及预后。方法。将我院1990－1999年中的133例AMI病人分为老年组（97例）和非老年组（36例）,分析两组的临床症状,主要并发症,住院病死率及死亡原因,结果：老年组中不典型或无明显我痛者多,泵衰竭或心律失常的发展率及住院病死率高,死亡原因依次为泵衰竭,休克及恶性心律失常,结论：老年性AMI症状不典型,并发症多,死亡率高,泵衰竭是老年AMI的主要死亡原因。     

Primary coronary angioplasty vs thrombolysis for the management of acute myocardial infarction in elderly patients.

CONTEXT: Despite evidence from randomized trials that, compared with early thrombolysis, primary percutaneous transluminal coronary angioplasty (PTCA) after acute myocardial infarction (AMI) reduces mortality in middle-aged adults, whether elderly patients with AMI are more likely to benefit from PTCA or early thrombolysis is not known. OBJECTIVE: To determine survival after primary PTCA vs thrombolysis in elderly patients. DESIGN: The Cooperative Cardiovascular Project, a retrospective cohort study using data from medical charts and administrative files. SETTING: Acute care hospitals in the United States. PATIENTS: A total of 20683 Medicare beneficiaries, who arrived within 12 hours of the onset of symptoms, were admitted between January 1994 and February 1996 with a principal discharge diagnosis of AMI, and were eligible for reperfusion therapy. MAIN OUTCOME MEASURES: Thirty-day and 1-year survival. RESULTS: A total of 80356 eligible patients had an AMI at hospital arrival and met the inclusion criteria, of whom 23.2% received thrombolysis and 2.5% underwent primary PTCA within 6 hours of hospital arrival. Patients undergoing primary PTCA had lower 30-day (8.7% vs 11.9%, P=.001) and 1-year mortality (14.4% vs 17.6%, P=.001). After adjusting for baseline cardiac risk factors and admission and hospital characteristics, primary PTCA was associated with improved 30-day (hazard ratio [HR] of death, 0.74; 95% confidence interval [CI], 0.63-0.88) and 1-year (HR, 0.88; 95% CI, 0.73-0.94) survival. The benefits of primary coronary angioplasty persisted when stratified by hospitals' AMI volume and the presence of on-site angiography. In patients classified as ideal for reperfusion therapy, the mortality benefit of primary PTCA was not significant at 1-year follow-up (HR, 0.92; 95% CI, 0.78-1.08). CONCLUSION: In elderly patients who present with AMI, primary PTCA is associated with modestly lower short- and long-term mortality rates. In the subgroup of patients who were classified as ideal for reperfusion therapy, the observed benefit of primary PTCA was no longer significant.     

急性心肌梗死患者行经皮冠状动脉介入术后住院期间死亡的危险因素分析

目的 探讨影响急性心肌梗死(AMI)患者行经皮冠状动脉介入术(PCI)后住院期间死亡的危险因素.方法 回顾性分析2009年1月至2011年9月因AMI入住我院并行PCI的275例患者的一般情况、既往史、入院情况、术中及术后情况、并发症等资料,对可能影响术后死亡的危险因素通过logistic回归模型进行分析.结果 多因素logistic回归分析表明,女性( P=0.047,OR=2.91)、广泛前壁心肌梗死(P=0.044,OR=3.07)、肾功能不全史(P=0.021,OR=7.98)、发生心源性休克(P=0.008,OR=15.71)、术后心肌梗死溶栓(TIMI)血流＜3级(P=0.016,OR=5.61)、置入主动脉内球囊反搏(IABP;P=0.043,OR=3.49).结论 影响AMI患者行PCI术后院内死亡的危险因素为女性、广泛前壁心肌梗死、置入IABP、术后TIMI血流＜3级、肾功能不全史和发生心源性休克.     

急性心肌梗死伴心衰、心源性休克病人经皮冠状动脉介入治疗近中期疗效

OBJECTIVE: To observe the short- and mid-term effects of percutaneous coronary intervention (PCI) in patients with ST-segment elevation acute myocardial infarction (AMI) complicated by heart failure and/or cardiogenic shock . METHODS: Altogether 90 patients with AMI were recruited, of whom 58 were treated by PCI, 20 by thrombolytic therapy, and the other received general treatment without reperfusion therapy. The length of hospital stay, major adverse cardiac events (MACE) and left ventricular ejection fraction (LVEF) were compared between PCI and thrombolysis groups. The relationship between the patency time of the infarct-related artery (IRA), thrombolysis in myocardial infarction (TIMI) grade after PCI and prognosis were analyzed in PCI group. RESULTS: The patency rate of IRA was significantly improved in patients receiving PCI therapy in comparison by those with thrombolytic therapy (98.3% vs 65.0%, P<0.01), and the LVEF was also higher in PCI group with lower mortality (6.9% vs 25.0%, P<0.05) during in-hospital and follow-up period. CONCLUSION: PCI can be a more effective therapy than thrombolytic therapy in the treatment of ST-segment elevation AMI accompanied with heart failure and/or cardiogenic shock.     

Health outcomes associated with various antihypertensive therapies used as first-line agents: a network meta-analysis

CONTEXT: Establishing relative benefit or harm from specific antihypertensive agents is limited by the complex array of studies that compare treatments. Network meta-analysis combines direct and indirect evidence to better define risk or benefit. OBJECTIVE: To summarize the available clinical trial evidence concerning the safety and efficacy of various antihypertensive therapies used as first-line agents and evaluated in terms of major cardiovascular disease end points and all-cause mortality. DATA SOURCES AND STUDY SELECTION: We used previous meta-analyses, MEDLINE searches, and journal reviews from January 1995 through December 2002. We identified long-term randomized controlled trials that assessed major cardiovascular disease end points as an outcome. Eligible studies included both those with placebo-treated or untreated controls and those with actively treated controls. DATA EXTRACTION: Network meta-analysis was used to combine direct within-trial between-drug comparisons with indirect evidence from the other trials. The indirect comparisons, which preserve the within-trial randomized findings, were constructed from trials that had one treatment in common. DATA SYNTHESIS: Data were combined from 42 clinical trials that included 192 478 patients randomized to 7 major treatment strategies, including placebo. For all outcomes, low-dose diuretics were superior to placebo: coronary heart disease (CHD; RR, 0.79; 95% confidence interval [CI], 0.69-0.92); congestive heart failure (CHF; RR, 0.51; 95% CI, 0.42-0.62); stroke (RR, 0.71; 0.63-0.81); cardiovascular disease events (RR, 0.76; 95% CI, 0.69-0.83); cardiovascular disease mortality (RR, 0.81; 95% CI, 0.73-0.92); and total mortality (RR, 0.90; 95% CI, 0.84-0.96). None of the first-line treatment strategies-beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, calcium channel blockers (CCBs), alpha-blockers, and angiotensin receptor blockers-was significantly better than low-dose diuretics for any outcome. Compared with CCBs, low-dose diuretics were associated with reduced risks of cardiovascular disease events (RR, 0.94; 95% CI, 0.89-1.00) and CHF (RR, 0.74; 95% CI, 0.67-0.81). Compared with ACE inhibitors, low-dose diuretics were associated with reduced risks of CHF (RR, 0.88; 95% CI, 0.80-0.96), cardiovascular disease events (RR, 0.94; 95% CI, 0.89-1.00), and stroke (RR, 0.86; 0.77-0.97). Compared with beta-blockers, low-dose diuretics were associated with a reduced risk of cardiovascular disease events (RR, 0.89; 95% CI, 0.80-0.98). Compared with alpha-blockers, low-dose diuretics were associated with reduced risks of CHF (RR, 0.51; 95% CI, 0.43-0.60) and cardiovascular disease events (RR, 0.84; 95% CI, 0.75-0.93). Blood pressure changes were similar between comparison treatments. CONCLUSIONS: Low-dose diuretics are the most effective first-line treatment for preventing the occurrence of cardiovascular disease morbidity and mortality. Clinical practice and treatment guidelines should reflect this evidence, and future trials should use low-dose diuretics as the standard for clinically useful comparisons.     

Early statin treatment following acute myocardial infarction and 1-year survival

CONTEXT: Randomized trials have established statin treatment as secondary prevention in coronary artery disease, but it is unclear whether early treatment with statins following acute myocardial infarction (AMI) influences survival. OBJECTIVE: To evaluate the association between statin treatment initiated before or at the time of hospital discharge and 1-year mortality after AMI. DESIGN AND SETTING: Prospective cohort study using data from the Swedish Register of Cardiac Intensive Care on patients admitted to the coronary care units of 58 Swedish hospitals in 1995-1998. One-year mortality data were obtained from the Swedish National Cause of Death Register. PATIENTS: Patients with first registry-recorded AMI who were younger than 80 years and who were discharged alive from the hospital, including 5528 who received statins at or before discharge and 14 071 who did not. MAIN OUTCOME MEASURE: Relative risk of 1-year mortality according to statin treatment. RESULTS: At 1 year, unadjusted mortality was 9.3% (1307 deaths) in the no-statin group and 4.0% (219 deaths) in the statin treatment group. In regression analysis adjusting for confounding factors and propensity score for statin use, early statin treatment was associated with a reduction in 1-year mortality (relative risk, 0.75; 95% confidence interval, 0.63-0.89; P =.001) in hospital survivors of AMI. This reduction in mortality was similar among all subgroups based on age, sex, baseline characteristics, previous disease manifestations, and medications. CONCLUSIONS: Early initiation of statin treatment in patients with AMI is associated with reduced 1-year mortality. These results emphasize the importance of implementing the results of randomized statin trials in unselected AMI patients.