Search

Understanding of the mechanisms, outcomes and treatment of non-Q wave myocardial infarction (NQMI) has evolved. Coexisting diabetes poses additional challenges. We studied baseline characteristics, in-hospital and one-year outcomes for NQMI patients having percutaneous transluminal angioplasty.

The genetic defect of coagulation factor V known as factor V Leiden produces a resistance to degradation by activated protein C (APC) and increases the risk of venous thromboembolism. The data on arterial thrombosis associated with APC resistance are still not clearly defined. We conducted a study in patients presenting with acute myocardial infarction (MI) to assess whether factor V Leiden increases the risk of arterial thrombosis. We studied 109 patients who had a diagnosis of acute MI (69 males and 40 females, aged 25-91 years), and 112 controls. The study population was identified by characteristic ECG changes and elevation of serum CK-MB, whereas the control subjects were anonymous healthy blood donors with no known history of coronary artery disease. Blood samples from the patients and controls were analyzed for the factor V Leiden mutation by DNA analysis, using the polymerase chain reaction. Heterozygous factor V Leiden mutation was found in 9 of 109 (8%) MI patients and 5 of 112 (4%) control subjects (P =.42). In conclusion, this study shows no evidence of an association between factor V Leiden and acute MI.

Background: We analyzed the risk factors and outcomes associated with non-Q wave myocardial infarction (MI) in females and males. We studied 376 consecutive patients N 275 males (73%) and 101 females (27%) N who presented with non-Q wave MI and had percutaneous transluminal coronary angioplasty (PTCA) prior to discharge during the period between January 1992 and February 1996., Results: Females were significantly older (68 +/- 10 years vs. 61 +/- 11 years; p < 0.001) and had more hypertension (67% vs. 51%; p < 0.01). Males had a slightly lower ejection fraction (47 +/- 11%) compared to females (50 +/- 10%; p < 0.001). Angioplasty was equally successful for women and men (96% vs. 97%; p = NS) with a statistically significant smaller number of lesions dilated per patient in females (1.38 vs. 1.51; p < 0.04). There were no significant differences in unstable angina, prior coronary artery bypass graft (CABG) surgery, saphenous vein graft PTCA, single vessel versus multiple vessel disease or history of prior MI. In-hospital complications (i.e., the need for CABG or repeat PTCA, recurrent MI, and stroke) were not statistically significant for either females or males. There was a trend for a higher in-hospital death rate in females after a non-Q wave MI, but it was not statistically significant (4% vs. 1%; p = 0.058). However, at one-year follow-up females had a significantly worse survival rate than men (89% vs. 95%; p < 0.04), although event-free survival rate was similar (61% female, 66% male; p = NS). CABG was performed less commonly in women by the end of one year (p < 0.02) than in men, while the performance of PTCA was similar., Conclusions: Although women with non-Q wave MI presented with more risk factors than men, in-hospital revascularization was equally successful with few complications and morbid events and similar event-free outcome at one year. However, one year mortality was worse for women, suggesting a need for more aggressive follow-up evaluation and treatment. For both women and men, this aggressive percutaneous revascularization strategy resulted in much better outcome than previously reported for medical treatment of non-Q wave MI.

Risk factors and outcomes associated with non-Q-wave myocardial infarction (MI) in diabetics and nondiabetics were analyzed for 376 consecutive patients, 77 with diabetes (20%) and 299 nondiabetics (80%), who had non-Q-wave MI and had percutaneous transluminal coronary angioplasty (PTCA) performed before discharge from hospital during the period from January 1992 to February 1996. Diabetics were slightly older (64 +/- 10 years vs 61 +/- 12 years, p <0.053), had more prior coronary artery bypass grafting (CABG) surgery (27% vs 12%, p <0.001), and hypertension (77% vs 49%, p <0.001). There was no significant difference in unstable angina, saphenous vein graft PTCA, single versus multiple vessel disease, or history of MI. PTCA success rates for diabetics versus nondiabetics were similar (96% vs 97%, p = NS). In-hospital complications such CABG, recurrent MI, repeat PTCA, stroke, and death were not statistically significant between the 2 groups. At 1-year follow-up, survival in diabetics (92%) was similar to nondiabetics (94%, p = NS), although event-free survival (PTCA, CABG, MI, death) was worse in diabetics (55% vs 67% for nondiabetics, p <0.05). Although diabetic patients with non-Q-wave MI represent a cohort with more risk factors for poor outcome, aggressive in-hospital revascularization with PTCA results in an excellent short-term outcome as well as 1-year survival similar to the nondiabetic patients. However, total events at 1-year follow-up are more common in the diabetic patients, suggesting that more aggressive screening and therapy in follow-up may be warranted, and that a diabetic with non-Q-wave MI will require increased utilization of cardiovascular resources in the first year after the event.

Gender-related differences in outcome after myocardial infarction may relate to biased treatment allocation. To address this concern we analyzed 573 patients presenting with ST-segment elevation acute myocardial infarction (AMI), and treated within 6 hours with reperfusion therapy. Two-hundred eighty patients (49%) received direct coronary angioplasty, whereas 293 (51%) received thrombolytics followed by angioplasty (p = NS). Seventy-four percent were men and 26% were women (p = NS for differences in sex distribution between the 2 treatment groups). Women were older in both groups (p < 0.01). Inferior AMI was seen more often in women (64% of direct angioplasty, 71% of lytic first) than in men (51% and 59%, respectively; p < 0.03). There was no gender-related differences in presence of multivessel coronary artery disease, prior AMI, prior bypass surgery, baseline ejection fraction, percentage of patients with ejection fraction < or = 40%, number of narrowings dilated, or angioplasty success. Patients who underwent direct angioplasty had more multivessel disease (p < 0.001) and prior coronary artery bypass surgery (p = 0.002). After a mean follow-up of 129 +/- 113 weeks, no gender-related differences were seen in the need for cardiac catheterization, documented restenosis, AMI, coronary artery bypass surgery, clinical ischemia, or death. Patients treated with direct angioplasty were more likely to undergo coronary artery bypass surgery (p < 0.05) or to die (p < 0.01). Thus, women undergoing reperfusion therapy for ST-segment elevation were older than men, with a higher frequency of inferior wall AMI. No specific gender-related bias in treatment allocation was evident.

The timing and mechanisms of early (30 day) mortality in 330 consecutive patients treated with direct angioplasty less than 12 hr after onset of myocardial infarction without antecedent thrombolysis were studied. There were 38 deaths (11.5% of pts), with a majority being due to cardiogenic shock (76%). Other causes included acute closure (11%), death after emergency bypass surgery (5%), ventricular arrhythmias (5%), and respiratory failure (3%). No deaths from stroke or cardiac rupture were seen, in contrast to trials of thrombolytic agents. Most deaths were seen early, with 47% occurring within 1 day, 35% from days 2-7, and 18% from days 8-30. Death from cardiogenic shock was the most common cause of death throughout this period: 83% of deaths in days 0-3, 88% of deaths in days 4-6, and 43% of deaths in days 8-30. Significant predictors of early death included older age (P < .0001), multi-vessel disease (P < .05), direct angioplasty failure (P < .05), reduced ejection fraction (P < .0001), and anterior myocardial infarction (P < .0005). Gender, prior myocardial infarction, and prior bypass surgery did not affect mortality. Cardiogenic shock is the most common cause of early death after direct angioplasty for myocardial infarction. Patients with one or more risk factors for early death may benefit from additional myocardial salvage or revascularization efforts in the early post-infarct period. Certain causes of death after direct angioplasty (cardiac, rupture, stroke) appear to be less common than data reported for lytic therapy for myocardial infarction.

Both direct angioplasty and thrombolytic therapy can decrease mortality from acute myocardial infarction, but certain subgroups of patients benefit more from one method than the other. Direct angioplasty is favored in patients in cardiogenic shock (with perhaps the exception of those who are elderly or have three-vessel coronary disease) and patients who have undergone previous coronary bypass surgery. Thrombolytic therapy and direct angioplasty seem to be equally effective in patients with acute myocardial infarction who present more than 6 hours after onset of symptoms or have multivessel coronary artery disease. The location of the infarct (anterior versus inferior) does not favor one therapy over the other. We believe that in most patients, the best approach is to begin with thrombolytic therapy and to follow that with selective application of angioplasty when it is clinically appropriate.

There is little question that reperfusion therapy with thrombolytic agents benefits patients who meet the current eligibility requirements and receive therapy shortly after acute myocardial infarction. Less clear is whether this therapy would benefit and be safe for use in patients who are now deemed ineligible to receive it. The authors compare the three available intravenous thrombolytic agents, summarize the risks and benefits associated with thrombolytic therapy in various situations, and make recommendations based on their experience.

Physicians should consider oxygen, morphine, nitrates, beta blockers, and aspirin as the foundation of early adjunctive treatment of acute myocardial infarction. An angiotensin-converting enzyme (ACE) inhibitor should be considered after 72 hours of adjunctive treatment. Intravenous heparin therapy is useful in certain subsets of patients, and intravenous magnesium therapy shows promise. With the exception of beta blockers, prophylactic antiarrhythmic agents are currently not indicated. We predict that combination therapy with aspirin, a beta blocker, and an ACE inhibitor will assume an ever-increasing role in treatment of myocardial infarction.

Six hundred one consecutive patients undergoing reperfusion within 6 hours of acute myocardial infarction were studied with regard to impact of previous coronary artery bypass grafting (CABG) on direct coronary angioplasty performance and results. Forty-nine patients (8%) had previously undergone CABG, whereas 552 (92%) had not. Direct angioplasty was used for reperfusion in 35 patients (71%) in the CABG group, and in 258 (47%) in the non-CABG group (p < 0.01). No significant differences between these groups were noted with regard to gender, age, infarction site, time to reperfusion or angioplasty success (34 of 35 CABG patients [97%] vs 236 of 258 non-CABG patients [92%]). CABG patients were more likely to have had previous infarction (17 of 35 [49%] vs 35 of 258 [14%] [p < 0.001]), multivessel disease (34 of 35 [97%] vs 127 of 258 [49%] [p < 0.001]) and lower mean ejection fraction (0.36 +/- 0.13 vs 0.46 +/- 0.12, p < 0.001). Over a mean follow-up of 151 weeks, 24 patients (69%) in the CABG group were restudied versus 112 (43%) in the non-CABG group (p < 0.01). Restenosis occurred in 14 patients (40%) in the CABG group versus 58 (22%) in the group without previous CABG (p = 0.04). In the CABG group, restenosis occurred significantly more often in saphenous vein grafts than in native vessels (12 of 17 [71%] vs 2 of 11 [18%] [p < 0.02]). There was no significant difference in the overall performance of repeat angioplasty between the 2 groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Important sex-related differences have been recognized in several coronary artery disease presentation and treatment subsets. Little data exist describing the relative findings and outcome in women versus men who received direct percutaneous transluminal coronary angioplasty for acute myocardial infarction. We studied 670 such patients of whom 464 (69%) were men and 206 were women. The women were significantly older (67 +/- 11 years vs 61 +/- 11, p < 0.001) but had undergone less prior coronary artery bypass graft surgery (6% vs 12%, p = 0.02), whereas prior myocardial infarction (17% women vs 22% men) and coronary artery disease distribution were not significantly different. Forty-one percent of women and 43% of men had single-vessel disease (p = NS). Both women and men had 1.5 lesions/patient dilated acutely, with similar success rates (95% women, 91% men; p = 0.08). Mean ejection fractions were similar (48% in both groups), and a similar percentage in each group had an ejection fraction < 30% (10% women vs 13% men). Over a mean follow-up period of 86 weeks, the need for repeat catheterization was frequent and was similar in both groups (44% women, 47% men; p = NS), whereas documented restenosis was less common in women (20% vs 28% of patients, p < 0.05). The need for coronary artery bypass grafting was similar (15% women, 17% men; p = NS), as was the need for repeat percutaneous transluminal coronary angioplasty in the infarct vessel (14% women, 18% men; p = NS) and overall mortality (7% women, 9% men; p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

We retrospectively studied the outcomes of patients with acute myocardial infarction who were treated with either direct angioplasty or thrombolytics followed by angioplasty. Two patient cohorts were analyzed: a previously reported (in regard to short-term follow-up) group of 371 patients who now have long-term follow-up (mean, 3.4 years) of survival and event-free survival and a second group of 202 patients who have been treated since publication of our initial data. Both 1-year and 2-year survival were significantly better (p = 0.01 and 0.02, respectively) in the group that was treated with thrombolytics first. Event-free survival (i.e., no myocardial infarction, coronary artery bypass graft surgery, repeat angioplasty) was better overall (p < 0.01) for the group that was treated with thrombolytics first. The more recently treated group of patients also showed benefit in regard to both survival (p = 0.002) and event-free survival (p < 0.01) over a short-term follow-up period (mean, 39 weeks) for patients who were treated initially with thrombolytics as compared with those who were treated with direct angioplasty. Although the initial cohort was very similar to the treatment groups except for age (mean age for the direct angioplasty group was 62 +/- 12 years vs 57 +/- 11 years for thrombolytics first group, (p = 0.0002), several differences existed in the more recent treatment groups. The patients who were more recently treated with direct angioplasty were older, had lower mean ejection fraction, had more extensive coronary artery disease, and were more likely to have had prior coronary artery bypass grafting.(ABSTRACT TRUNCATED AT 250 WORDS)

Unlabelled: We studied 417 patients undergoing single vessel culprit lesion percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction to determine the impact of disease in other vessels. Group A (189 patients, 45%) had coronary artery disease (greater than or equal to 70% stenosis) in at least 1 additional vessel while Group B (228 patients, 55%) did not. The groups were similar in sex distribution (A = 75% male, B = 76%), number of lesions in the single culprit vessel dilated (1 lesion in 83% A, 80% B), and PTCA success (A = 92%, B-94%) (all p = NS). Group A patients were older (63 +/- 10 vs. 56 +/- 11 years) and had more prior myocardial infarctions (27% vs. 7%), and more prior coronary artery bypass grafting (15% vs. 0.4%) (all p less than .01). Group A patients were more likely to have repeat catheterization (48% vs. 32%, p less than .005) although restenosis of the infarct-related vessel was similar (A = 24%, B = 16%) (p = NS). Group A was more likely to need angioplasty in a 2nd vessel (23% vs. 8%) and to need coronary artery bypass grafting (20% vs. 8%) (both p less than .001). Cumulative mortality was higher in Group A at 1 month (10% vs. 5%), 1 year (11% vs. 6%), and long-term (13% vs. 7%). This difference appeared to be due to the impact of lower mean ejection fraction in Group A., Conclusion: Treatment of acute myocardial infarction by direct PTCA of the culprit lesion can be performed with a high likelihood of success in patients with or without multivessel coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

To compare the results and outcome of different management approaches for acute myocardial infarction, we analyzed our experience with early (i.e., within 6 hours of infarct onset) direct percutaneous transluminal coronary angioplasty (group A) versus initial treatment with thrombolytic therapy (group B) followed by angioplasty. From 1982 to 1989 a total of 214 patients underwent primary angioplasty for acute myocardial infarction. During this time 157 patients underwent initial thrombolytic therapy, 104 with intravenous streptokinase and 53 with intravenous tissue-type plasminogen activator followed by angioplasty. Other than age (group A, 61.7 +/- 11.5 years; group B, 57.3 +/- 11.6 years; p = 0.0002), the clinical characteristics of the groups were similar. In group A, 197 (92.1%) had successful results, and 17 (7.9%) were failures. Of the group treated with thrombolytic therapy, there was an overall 81.5% patency rate for patients treated with streptokinase and tissue-type plasminogen activator with no significant difference between the agents. Angioplasty success after thrombolytic therapy was 94.3%. In-hospital and 1-year survival was significantly better in group B patients (95.5% and 95.5%, respectively) than in group A patients (92.1% and 89.3%, respectively). We conclude that both direct angioplasty and thrombolytic therapy followed by angioplasty provide high recanalization rates but that short- and long-term survival is improved when thrombolytic therapy precedes angioplasty in acute myocardial infarction patients.

The first electrocardiogram obtained on presentation for suspected myocardial infarction was examined for its usefulness in predicting clinical course and facility use. We studied 221 patients consecutively admitted to a nonuniversity hospital coronary care unit. High-risk patients were identified if the electrocardiographic diagnoses included myocardial infarction, ischemia, left ventricular hypertrophy, left bundle-branch block, or paced rhythm. These 63 patients (29% of total) had significantly greater incidences of serious events, need for procedures, and death than low-risk patients whose initial electrocardiograms did not carry the above diagnoses. Patients with a low-risk initial electrocardiogram may not require the facilities of a coronary care unit and perhaps could be safely observed in an intermediate care area. However, many hospitals do not have an intermediate care facility available, and in those that do, daily costs may not be markedly different than for treatment in a coronary care unit. Whether these low-risk patients could be safely treated in general medicine beds, where potential cost savings would be much greater, is unknown.

We reviewed the records of 2,400 consecutive patients undergoing cardiac catheterization at USAF Medical Center Keesler between 1978 and 1984 and found 35 patients (1.5 percent of all cardiac catheterizations) aged 35 years or less (mean age, 32 years) who underwent cardiac catheterization after myocardial infarction. These 35 patients (group 1) were compared to a randomly selected group of 100 patients (group 2) aged 55 years or greater who underwent cardiac catheterization for evaluation of coronary artery disease during the same period. The two groups were compared in terms of angiographic features and risk factors for coronary artery disease. The patients in group 1 had a higher proportion of normal coronary arteries (14 percent [5 patients] vs 0; p less than 0.01) and single-vessel disease compared to group 2, while the incidence of three-vessel disease was much less (14 percent [5] vs 47 percent; p less than 0.001). Involvement of the left main coronary artery was uncommon in group 1 (3 percent [1] vs 15 percent in group 2; p less than 0.01). Risk factor analysis revealed smoking to be the most common risk factor in both groups (89 percent [31] in group 1 and 91 percent in group 2). Hypertension (28 percent [10] vs 48 percent; p less than 0.05) and diabetes (3 percent [1] vs 23 percent; p less than 0.01) were more common in group 2. Importantly, of 19 patients in group 1 who underwent cardiac catheterization for prognosis despite being asymptomatic and able to reach at least stage 4 on a Bruce protocol exercise test, none was found to have residual surgically correctable disease.