Higher Risk Of Acute Myocardial Infarction Research Articles

Menopause and risk of non-fatal acute myocardial infarction: an Italian case-control study and a review of the literature.

The relationship between menopause and non-fatal acute myocardial infarction (AMI) was considered by analysing data from a case-control study conducted in Italy between 1983 and 1992. Cases were 429 women, below age 75 years, with a first episode of non-fatal AMI, admitted to 30 coronary care units; controls were 863 women admitted to the same network of hospitals for acute diseases other than cardiovascular, neoplastic, or hormone-related. Postmenopausal women were not at higher risk of AMI than pre/perimenopausal women, after adjustment for age and other selected covariates [multivariate odds ratio (OR) 0.99]. With reference to age at menopause, compared with women reporting menopause when <45 years, the multivariate OR were 1.54 for those aged 45-49 at menopause, 1.36 for those aged 50-52 years, and 0.97 for those aged >/=53, in the absence of any trend in risk. No meaningful relationship emerged with time since menopause (OR 0.85 for <10 years since menopause). The results were similar in women aged <60 and >/=60 years at AMI. Although the present study does not support a substantial relationship between menopause and non-fatal AMI, the overall epidemiological evidence is compatible with a moderate association.

A prediction model for prehospital triage of patients with suspected cardiac ischemia

The American College of Cardiology recommends that patients with high risk acute myocardial infarction (AMI) be triaged to hospitals with percutaneous transluminal coronary angioplasty capability. However, there are no prehospital triage criteria to select candidates for bypassing community hospitals and being taken directly to “cardiac centers.” This article assesses which independent variables predict death within 7 days in patients with suspected AMI transported by EMS. This is a retrospective study of 291 AMI patients transported by ambulance to 3 hospitals during 1996–1997. Included were patients who were (n=244)≥18 years of age, had a ED chief complaint of chest pain or dyspnea for whom we had mortality data. Mortality at 7 days, our primary outcome measure, was obtained by using a metropolitan Detroit tricounty death index records. Differences between the survivors and nonsurvivors were assessed using the Student's t-test and chi-square tests. Multiple triage criteria were assessed for optimal identification of high risk patients by constructing a logistic multivariate model. Among the study population, 15% died within 7 days (95% confidence interval (CI) 10.3–19.2), and this group represented 63.2% of all deaths over a 2 year surveillance period. Survivors, compared to nonsurvivors, were 14.1 years younger ( P≤.001) and more often men ( P<-0.001). The dispatch time to ED arrival was less among survivors than nonsurvivors (42.8 vs. 50.6 min, P<0.1). EMS vital signs differed by survivor status. Among survivors, HR was lower (−11.9 bpm; P<0.01), RR was lower (−6.7 rpm; P≤.001), SBP was higher (+14.5 mmHg; P≤0.05) and DBP was higher (+13.2 mm Hg; P≤.01). A Multivariate model identified the following as independent predictors of early mortality: female gender (OR=2.3; P≤.05), age ≥65 (OR=5.9; P≤.01), RR≥20 (OR=4.6; P≤.001), SBP<120 (OR=2.4; P≤.05). The overall model was 86% sensitive and 53% specific with an area under the receiving operating characteristic curve of 0.8 ( P≤.001). A triage rule based on a multivariate model can identify the group at high risk of early cardiac death. This decision rule needs to be prospectively validated.

Electrocardiographic and Clinical Predictors of Acute Myocardial Infarction in Patients With Unstable Angina Pectoris

Among patients with unstable angina pectoris (UAP), those who have non–ST-elevation acute myocardial infarction (AMI) are at higher risk for subsequent adverse events. To determine predictors of AMI in patients with UAP, we studied consecutive nonreferral patients with UAP or AMI admitted from the emergency department to the intensive care or telemetry units of an urban teaching hospital over 1 year. There were 280 study patients (mean age 66 years, 1/3 women); 24% had AMI at presentation, whereas 76% had UAP without evidence of AMI. Thresholds of ≥3 involved leads (odds ratio [OR] 3.3; 95% confidence intervals [CI] 1.6 to 6.9) and ≥0.2 mV (OR 5.1; 95% CI 2.2 to 11.6) of ST depression on the presenting electrocardiogram were strongly associated with AMI. The multivariate predictors of AMI were reported duration of symptoms >4 hours (OR 3.8; 95% CI 1.9 to 7.3), absence of prior revascularization (OR 3.5; 95% CI 1.6 to 7.5), absence of β-blocker use before presentation (OR 2.8; 95% CI 1.3 to 5.8), and presence of new ST depression (OR 2.8; 95% CI 1.4 to 5.7). Using the 4 multivariate predictors, a prediction rule was developed. The percentages of patients with AMI when 0, 1, 2, 3, or 4 characteristics were present, respectively, were 7%, 6%, 24%, 46%, and 83% (p <0.001). A similar prediction rule developed from the Thrombolysis In Myocardial Ischemia III trial was validated in our cohort. Among patients with UAP, electrocardiographic and clinical variables can help immediately identify those at high risk for AMI at presentation.

Bcl I polymorphism in the fibrinogen beta-chain gene is associated with the risk of familial myocardial infarction by increasing plasma fibrinogen levels. A case-control study in a sample of GISSI-2 patients.

The aim of this study was to investigate the association of the Bcl I beta-chain fibrinogen polymorphism with the risk of acute myocardial infarction (AMI) and its relationship with fibrinogen levels in the Italian population. We studied 102 AMI patients, selected within the framework of the GISSI-2 trial, who had a familial history of arterial thrombosis (at least one first-degree relative suffering from AMI or stroke before 65 years) and 173 control subjects (with neither AMI nor personal or familial history of arterial thrombosis). All subjects were Italian. Patients showed fibrinogen levels higher than control subjects. There was a highly significant difference in allele frequency in cases versus control subjects, the B2 allele frequencies being respectively 0.28 versus 0.17 (P = .002). In multivariate analysis, adjusted for sex, age, smoking habits, and history of hyperlipidemia, hypertension, or diabetes, the (B1B2 + B2B2) genotype was associated with a higher risk of AMI (odds ratio 2.4, 95% confidence interval, 1.2 to 4.6). The Bcl I genotype was also associated with fibrinogen levels, independently of gender and smoking habits, the (B1B2 + B2B2) subjects showing the highest levels in both cases and control subjects. The difference in fibrinogen levels between cases and control subjects was significantly influenced by the genotype (significant interaction, P = .042). The B2 allele of the Bcl I polymorphism in the beta-chain of the fibrinogen gene is a new factor associated with the risk of familial AMI through its association with fibrinogen levels. These data provide evidence for a causal role of fibrinogen in familial AMI.

Clinical aspects of ACE inhibition in patients with acute myocardial infarction

The purpose of the present article was to review the current evidence on the use of angiotensin-converting enzyme (ACE) inhibitors in acute myocardial infarction (MI). This article is based on published information as well as on our personal experience derived from an extensive analysis of the SMILE study. All the randomized trials have been included irrespective of the primary endpoint, and the results are presented in terms of either hemodynamic or clinical benefit. Short- and long-term treatment with ACE inhibitors in patients with acute MI results in a significant reduction in mortality, which is more evident in high risk patients (i.e., patients with left ventricular dysfunction, congestive heart failure on admission, or anterior myocardial infarction). Development and progression of congestive heart failure after myocardial infarction was significantly reduced by ACE inhibition, which also reduced the rate of reinfarction, the need for revascularization procedures, as well as the occurrence of ventricular arrhythmias, probably through a mechanism involving some drug-dependent effects. In conclusion, the available data strongly support a wide benefit associated with the use of ACE inhibitors in patients with high-risk acute MI.

782-6 Clinical and Angiographic Followup to a Prospective Study of Transluminal Extraction Atherectomy in High Risk Patients with Acute Myocardial Infarction

Acute myocardial infarction (AMI) patients with an infarct related artery (IRA) containing thrombus are a high risk group for percutaneous transluminal coronary angioplasty. TEC may be a useful device for treatment of these patients due to its ability to aspirate thrombus. TEC was prospectively evaluated in 63 patients (age 61 ± 12 years) including 23 (36.5%) ineligible for thrombolysis, 24 (38%) with lytic failure, and 16 (25.5%) with post infarct angina and a thrombotic coronary occlusion. Immediate, one week, and six month angiographic and clinical followup were obtained. The IRA was a SVG in 18 (29%) and a native coronary artery (NAT) in 45 (71%). Acute procedural success with a residual stenosis &lt; 50% and TIMI 2 or 3 grade flow was acheived in 94% of patients. There were no major procedural complications. Other events during the hospitalization included death in 3 (4.8%), CABG in 2 (3%) and blood transfusion in 12 (19%). Elective predischarge angiography revealed an IRA stenosis &lt; 50% in 34/38 (89%). Patients were followed for 6 months with clinical followup in 100% and angiographic in 38/63. Death CABG Patency at F/U IRA RePTCA NAT 3/45 (6.7%) 1145 (2.2%) 29/31 (94%) 15/45 (33%) SVG 4/18 (22.2%) 2/18 (11.1%) 4/7 (57%) 4/18 (22%) TOTAL 7/63 (11.1%) 3/63 (4.8%) 34/38 (90%) 19/63 (30%) Angiographic restenosis occurred in 27/38 (71%) although most patients returned for followup cath secondary to symptom recurrence. Clinical restenosis occurred in 22 (42%). High risk AMI patients can be successfully treated with TEC with a high technical success rate and a low incidence of complications. IRA patency at 1 week and 6 months was excellent; however, angiographic restenosis remains a problem. Extraction of thrombus in AMI may help maintain vessel patency but does not appear to prevent restenosis.

Secondary prevention after high-risk acute myocardial infarction with low-dose acebutolol

Acebutolol et Prévention Secondaire de l'Infarctus (APSI), a randomized, placebo-controlled trial, was designed to test long-term acebutolol, 200 mg twice daily, a β blocker with mild intrinsic sympathomimetic activity, in the prevention of late death in high-risk postacute myocardial infarction (AMI) patients. APSI was planned because patients with a death rate >20% have not been enrolled in significant numbers in previous trials and in such high-risk patients, it remained to be proven that β blockers have a beneficial effect. Patients with an expected average risk of >20% were to be selected based on clinical criteria. At the time of the second interim analysis, the placebo group 1-year mortality was much lower than expected (12%). The ethical board recommended to stop the trial: 309 patients had been allocated to placebo, 298 to acebutolol. The average delay between onset of symptoms and inclusion was 10.5 days. The average follow-up was 318 days after inclusion. About the same number of patients were discontinued from study treatment in both groups. All patients were included in the analysis. There were 17 deaths in the acebutolol group and 34 in the placebo group, a 48% decrease (p = 0.019). The vascular mortality decreased by 58% (p = 0.006), the highest ever observed with a β blocker. All cardiovascular causes of death, including congestive heart failure, were less frequent in the acebutolol group. Although the objective was not achieved, APSI patients were at a higher risk than the average of the 9 previous trials with β blockers (12% instead of 7%). In addition, the total mortality reduction did not decrease in 9 subgroups with increasing mortality risk from 2 to 23%. APSI shows that moderately severe postAMI patients can benefit from a β-blocking treatment and a β-blocker with mild intrinsic sympathomimetic activity can be effective.

Exercise performance of the high risk acute myocardial infarction patient after cardiac rehabilitation

Sixty-five subjects with a recent acute myocardial infarction (AMI), 50 men and 15 women aged 39 to 79 years (mean 62 ± 9), were entered into a 12-week phase II cardiac rehabilitation program. Group I subjects were those with an ejection fraction >40% (mean 56) and group II subjects were those with an ejection fraction <40% (mean 28). Subjects were further classified into those with or without myocardial ischemia (Ia, IIa and Ib, IIb, respectively) based on a treadmill stress test before entry. Work performance during the training sessions was similar for all subgroups, although group IIb had the lowest values for work rate and time of exercise for each individual activity. Subgroup analysis, as determined by a pre- and postprogram treadmill stress test, showed there was no significant difference in time of exercise, peak oxygen consumption and change in submaximal heart rate (decrease) for groups Ia, Ib or IIa. However, group IIb had poor performance in time of exercise (Δ = 2 ± 2 minutes), peak oxygen consumption (Δ = 3 ± 5 ml/min) and submaximal heart rate (Δ = 0.4 ±17 beats/min) compared with the 3 other subgroups. These subjects also did not demonstrate an improvement of these values in the posttraining period.Patients who have had AMI and have both significant left ventricular dysfunction and myocardial ischemia did not have an adequate training response after 12 weeks of a formal phase II cardiac rehabilitation program. Such patients may not benefit because of chronotropic incompetence and perhaps because of their inability to train at the same level as other lower risk patients.

Prognostic significance of progression of coronary artery disease

Angiographically documented coronary artery disease (CAD) can progress. Although progression itself is frequently recognized in patients who have undergone repeat cardiac catheterization, its prognostic significance remains unclear. To evaluate the influence of progression on survival, 313 patients with CAD who underwent catheterization twice (39 ± 25 months apart) were followed for 3 to 129 months (mean 41 ± 30) after the second angiogram. At the time of the second angiogram, 21, 91, 113 and 88 patients had 0-, 1-, 2- and 3-vessel CAD, respectively. The mean ejection fraction (EF) of the group was 55 ± 13%. Progression was noted in 139 patients (44%). Of the 313 patients, 33 died and 39 had acute myocardial infarction (AMI) during follow-up. Four-year survival was estimated at 94% and 83% in the nonprogression and progression groups, respectively. Progression was predictive of survival by (univariate) log-rank test (p < 0.01), but only EF (p < 0.001), number of diseased vessels (p < 0.01) and percent stenosis in the left main coronary artery (p < 0.05) were independently significant by (multivariate) Cox regression analysis. Four-year survival without AMI was 89% and 73% in the nonprogression and progression groups, respectively. Progression was related to survival without AMI (p < 0.001) by log-rank test. Cox regression analysis provided 3 independent predictors of survival without AMI: number of diseased vessels (p < 0.01), progression (p < 0.01, relative risk = 2.28) and EF (p < 0.01). Results were similar when analyzing only the 39 AMIs. Thus, for prediction of AMI, progression adds significant information beyond the current status of coronary anatomy and left ventricular function; patients with progressive CAD are at high risk of AMI.

The high-risk acute myocardial infarction patient at 1-year follow-up: Identification at hospital discharge by ambulatory electrocardiography and radionuclide ventriculography

The high-risk acute myocardial infarction patient at 1-year follow-up: Identification at hospital discharge by ambulatory electrocardiography and radionuclide ventriculography