Normal angiogram after myocardial infarction in young patients: a prospective clinical-angiographic and long-term follow-up study

Sex-Specific Risk Factors Associated With First Acute Myocardial Infarction in Young Adults

IMPORTANCE

An increasing proportion of people in the US hospitalized for acute myocardial infarction (AMI) are younger than 55 years, with the largest increase in young women. Effective prevention requires an understanding of risk factors associated with risk of AMI in young women compared with men.

OBJECTIVES

To assess the sex-specific associations of demographic, clinical, and psychosocial risk factors with first AMI among adults younger than 55 years, overall, and by AMI subtype.

DESIGN, SETTING, AND PARTICIPANTS

This study used a case-control design with 2264 patients with AMI, aged 18 to 55 years, from the VIRGO (Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients) study and 2264 population-based controls matched for age, sex, and race and ethnicity from the National Health and Nutrition Examination Survey from 2008 to 2012. Data were analyzed from April 2020 to November 2021.

EXPOSURES

A wide range of demographic, clinical, and psychosocial risk factors.

MAIN OUTCOMES AND MEASURES

Odds ratios (ORs) and population attributable fractions (PAF) for first AMI associated with demographic, clinical, and psychosocial risk factors.

RESULTS

Of the 4528 case patients and matched controls, 3122 (68.9%) were women, and the median (IQR) age was 48 (44-52) years. Seven risk factors (diabetes [OR, 3.59 (95% CI, 2.72-4.74) in women vs 1.76 (1.19-2.60) in men], depression [OR, 3.09 (95% CI, 2.37-4.04) in women vs 1.77 (1.15-2.73) in men], hypertension [OR, 2.87 (95% CI, 2.31-3.57) in women vs 2.19 (1.65-2.90) in men], current smoking [OR, 3.28 (95% CI, 2.65-4.07) in women vs 3.28 (2.65-4.07) in men], family history of premature myocardial infarction [OR, 1.48 (95% CI, 1.17-1.88) in women vs 2.42 (1.71-3.41) in men], low household income [OR, 1.79 (95% CI, 1.28-2.50) in women vs 1.35 (0.82-2.23) in men], hypercholesterolemia [OR, 1.02 (95% CI, 0.81-1.29) in women vs 2.16 (1.49-3.15) in men]) collectively accounted for the majority of the total risk of AMI in women (83.9%) and men (85.1%). There were significant sex differences in risk factor associations: hypertension, depression, diabetes, current smoking, and family history of diabetes had stronger associations with AMI in young women, whereas hypercholesterolemia had a stronger association in young men. Risk factor profiles varied by AMI subtype, and traditional cardiovascular risk factors had higher prevalence and stronger ORs for type 1 AMI compared with other AMI subtypes.

CONCLUSIONS AND RELEVANCE

In this case-control study, 7 risk factors, many potentially modifiable, accounted for 85% of the risk of first AMI in young women and men. Significant differences in risk factor profiles and risk factor associations existed by sex and by AMI subtype. These findings suggest the need for sex-specific strategies in risk factor modification and prevention of AMI in young adults. Further research is needed to improve risk assessment of AMI subtypes.

Association between fibrinogen level and the severity of coronary stenosis in 418 male patients with myocardial infarction younger than 35 years old

Fibrinogen (Fib) is a useful marker for predicting the severity of coronary artery disease (CAD) in adult population. However, whether Fib can be a predictor for the presence and severity of CAD in very young MI patients (≤35 years old) remains to be determined. A total of 418 males from 61,863 patients with MI who were under 35 years old were sequentially recruited in our study. The patients were divided into two main groups and three subgroups according to coronary angiograph and Gensini score (GS) system: no coronary artery stenosis (group A), the results of the coronary artery stenosis (group B); low GS, intermediate GS and high GS. Data indicated that Fib, body mass index, current smoking, white blood cell count (WBCC) and GS were significantly higher in group B than those in group A (all P < 0.01). Moreover, there were significant differences in Fib, mean age, diabetes mellitus, family history of CAD, WBCC, left ventricular ejection fraction, and GS between high GS and low GS subgroups (all P < 0.01). A positive correlation between Fib levels and GS was found (r = 0.242, p < 0.001). Receiver operating characteristics curve analysis demonstrated that the best cut-off level of Fib predicting the severity of coronary stenosis was 3.475g/L (sensitivity 64%; specificity 70%) and the area under the curve was 0.656. Fib was also independently associated with high GS (OR=2.173, 95%CI 1.011-4.670, P = 0.047) after adjusting for potential confounders. In conclusion, Fib is significantly related to the presence and severity of coronary stenosis in male patients with MI under 35 years old.

Characteristics and Long-Term Prognosis of Patients ≤35 Years of Age with ST Segment Elevation Myocardial Infarction and "Normal or Near Normal" Coronary Arteries

There are scarce data regarding risk factors and prognosis of patients with premature ST segment elevation myocardial infarction (STEMI) and "normal or near normal" coronary arteries (N/NNCAs). We compared the characteristics and long-term prognosis of patients with premature STEMI and N/NNCAs with their counterparts with significant coronary artery disease (CAD). We recruited 330 patients who had STEMI ≤35 years of age and 167 age- and gender-matched controls. All patients underwent coronary angiography. Coronary arteries with no lesions or lesions causing <30% reduction in lumen diameter were defined as N/NNCAs, whereas narrowings causing ≥50% diameter reduction formed the significant CAD group. Lipid profile, homocysteine levels, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism were determined. Sixty patients (18%) had N/NNCAs. Patients with N/NNCAs had lower low-density lipoprotein-cholesterol and higher high-density lipoprotein-cholesterol levels, higher homocysteine levels, and higher prevalence of MTHFR TT genotype (34.6 vs 18%, p = 0.008) compared with patients with significant CAD. After a median follow-up of 8 years, cardiovascular events occurred in 105 (36%) of 291 patients with available follow-up data. Significant CAD was associated with higher risk for recurrent cardiovascular events after adjustment for traditional risk factors (hazard ratio 2.095, 95% confidence interval 1.088 to 3.664, p = 0.022) and additional adjustment for the left ventricular ejection fraction, reperfusion therapy, and persistent smoking (hazard ratio 1.869, 95% confidence interval 1.007 to 3.468, p = 0.041). In conclusion, patients with premature STEMI and N/NNCAs have fewer lipid abnormalities, higher homocysteine levels and prevalence of MTHFR TT genotype, and better long-term prognosis compared with their counterparts with significant CAD.

Long-term outcomes of percutaneous coronary interventions with stent implantation in patients ≤40 years old

Data on the long-term prognosis of percutaneous coronary intervention (PCI) in young patients are limited. The aim of the present study was to report the immediate and long-term clinical outcomes in a consecutive series of young patients with premature coronary artery disease who underwent PCI with stent implantation. During the study period (2005 to 2010), 214 consecutive patients aged ≤40 years who had undergone PCI with a bare metal stent or drug-eluting stent implantation were retrospectively selected and analyzed. Primary end point of this study was the incidence of major adverse cardiac and cerebrovascular events at short- and long-term follow-up. Mean age was 36.3 ± 3.5 years and 88.3% of patients were men. Three-quarters were active smokers and all patients had ≥1 conventional cardiovascular risk factor. The total number of implanted stents was 272 (154 bare metal stent and 118 drug-eluting stent). During the hospital stay, no patient died, and the incidence of major adverse cardiac and cerebrovascular events was 2.3%. No additional events had occurred at 30 days of follow-up. At a median follow-up of 757 days (interquartile range 365 to 1,818), the overall death rate was 0.9%, and a new revascularization procedure was needed in 12.6% of patients. The major adverse cardiac and cerebrovascular event-free survival rate at the median follow-up point and 1,818 days was 89.6% and 84.2%, respectively. Active smoking and left ventricular ejection fraction <50% were independent predictors of major adverse cardiac and cerebrovascular events. In conclusion, PCI in young patients lead to excellent results in short- and long-term follow-up and should be considered as the treatment of choice. Traditional risk factors are important prognostic determinants of adverse events and might help identify higher risk patients within this cohort.

Is Myocardial Infarction in Patients without Significant Stenosis on a Coronary Angiogram as Benign as Believed?

The present study aimed to investigate the clinical characteristics and 1-year outcomes of acute myocardial infarction (AMI) patients without significant stenosis on a coronary angiogram comparison with the clinical characteristics and outcomes of patients with significant coronary artery stenosis. A total of 1,220 patients with AMI were retrospectively classified into Group I (≥50% diameter stenosis, n=1,120) and Group II (<50%, n=100). Group II was further divided into two subgroups according to the underlying etiology: cryptogenic (Group II-a, n=54) and those with possible causative factors (Group II-b, n=46). Patients in Group II were younger, were more likely to be women, and were less likely to smoke and to have diabetes mellitus than were patients in Group I. The levels of cardiac enzymes, LDL-cholesterol levels, and the apo-B/A1 ratio were lower in Group II. However, 1-month and 12-month rates of major adverse cardiac events (MACE) were not significantly different between the two groups. The Group II-b subgroup comprised 29 patients with vasospasm, 11 with myocardial bridge, and 6 with spontaneous thrombolysis. Left ventricular ejection fraction and creatinine clearance were lower and levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and high-sensitivity C-reactive protein (hs-CRP) were higher in Group II-a than in Group II-b. However, outcomes including MACE and mortality at 12 months were not significantly different between the two subgroups. The 1-year outcomes of patients in Group II were similar to those of patients in Group I. The clinical outcomes in Group II-a were also similar to those of Group II-b, although the former group showed higher levels of NT-proBNP and hs-CRP.

[Acute myocardial infarction in young smokers treated by coronary angioplasty. In-hospital prognosis and long-term outcome in a consecutive series of 93 patients]

AIMS OF THE STUDY

The study evaluated in-hospital and long-term outcome of patients less than 50 years old with myocardial infarction within 12 hours after symptom onset treated by coronary angioplasty.

PATIENTS AND METHOD

This is a retrospective study with survival analysis by Kaplan-Meier method in patients included from December 2003 to February 2008.

RESULTS

We included 93 patients aged 42,8+/-5,2 years old with smoking estimated at 27,7+/-12,7 pack-years. Thirty-one patients (33,3%) were dyslipidemic and 36 patients had family history of coronary artery disease. Thirty patients (32,3%) had an anterior myocardial infarction and four patients (4.4%) had Killip greater than 2. Coronary angioplasty was performed within 4.5+/-3.0 hours after symptom onset with TIMI 3 final flow in the culprit vessel in 96.8%. One patient died from cardiogenic shock. With a follow-up of 85 patients during 20.0+/-15.6 months, the survival without death was 98.2% and survival without major cardiac complication was 87.9% at 24 months. Seventy-two patients (85.7%) were taking a betablocker, 81 patients (96.4%) aspirin, 75 patients (89.3%) a statin and 64 patients (76.2%) an angiotensin-converting inhibitor. Only 50 patients (58.8%) were nonsmokers.

CONCLUSION

Thus, young smokers with acute MI treated by coronary angioplasty have a good prognosis during in-hospital stay and long-term outcome. Secondary medical treatment prevention is well followed but there is a low rate of smoking cessation.

Baseline clinical characteristics and midterm prognosis of STE-ACS and NSTE-ACS patients with normal coronary arteries

OBJECTIVE

We sought to compare clinical profiles and midterm prognosis of patients with normal coronary arteries presenting with ST-elevation ACS (STE-ACS) versus non-ST-elevation ACS (nSTE-ACS).

BACKGROUND

There are limited data regarding ACS in patients with normal coronary arteries, and especially clinical differences between ST-ACS and nSTE-ACS patients have not been evaluated sufficiently.

METHODS

The study group comprised 190 patients (mean age: 53.2 years, 63.1% males, 63.6% STE-ACS) presenting with ACS and normal coronary angiograms. The participants were evaluated in terms of 42 clinical variables. MACE [cardiac death (CD) and hospitalization for angina (HA)] were the study end points.

RESULTS

STE-ACS in comparison to nSTE-ACS patients were younger (P < 0.01), were more frequently males (P < 0.01), had more often infection prior to ACS (P < 0.01), higher hsCRP on admission (P < 0.01), and greater infarct size, measured by maximal troponin I (P < 0.01). By multivariate analysis in this subgroup, predictors of outcome were hsCRP (P = 0.03) and raised troponin I (P = 0.02). nSTE-ACS in comparison to STE-ACS patients were more obese (BMI, P < 0.01), had higher LDL cholesterol (P < 0.01), fasting glucose (P = 0.03). LDL cholesterol (P = 0.02) and fasting glucose (P = 0.03) emerged as independent predictors of outcome in these patients. Mean follow-up period was 25.4 months. STE-ACS patients had twice fewer MACE rate than nSTE-ACS patients [(1-CD, 12-HA; 11%) vs (1-CD, 16-HA; 25%), respectively, log rank P < 0.01].

CONCLUSIONS

STE-ACS and nSTE-ACS patients with normal coronary arteriography have different clinical profiles. In nSTE-ACS patients more pronounced metabolic abnormalities were identified, while in STE-ACS patients inflammatory background was more significant.

Myocardial infarction with angiographically normal coronary arteries in the contemporary era

BACKGROUND

Myocardial infarction with angiographically normal coronary arteries (MINC) is a well recognized clinical entity, but limited data regarding outcome and prognostic factors exist in the literature. This study sought to identify clinical characteristics and etiological factors as well as outcome predictors in patients with MINC.

DESIGN

Retrospective follow-up study.

METHODS

Fifty-eight patients presenting with MINC fulfilled the study inclusion criteria. Clinical characteristics, cardiovascular risk factors, and etiologic and laboratory data were harvested and compared with those obtained from patients with myocardial infarction and single vessel coronary artery disease (MISVD). Follow-up information regarding survival and cardiac events such as angina, reinfarction and heart failure was collected and prognostic factors identified.

RESULTS

Compared with the MISVD group, MINC patients had a lower prevalence of hypercholesterolemia and ST elevation. Hypercoagulopathy, collagen tissue disorder, cocaine abuse and Takotsubo cardiomyopathy were identified etiologies in some MINC patients. During follow-up, patients with MINC were less likely to sustain reinfarction (log-rank P<0.001) and cardiovascular death (log-rank P=0.04) on Kaplan-Meier survival analysis. Recurrence of angina and heart failure were the most prevalent cardiac events in the MINC group. Cox proportional multivariate regression analysis identified left ventricular ejection fraction as an independent predictor of cardiac events in the MINC cohort.

CONCLUSION

MINC is associated with lower mortality and morbidity compared with infarction in the setting of single vessel disease. Left ventricular function is an independent predictor of poor outcome.

[Myocardial infarction with ST segment elevation and angiographically normal coronary arteries: epidemiology and mid-term follow-up]

BACKGROUND AND OBJECTIVE

The myocardial infarction (MI) with ST elevation and angiographically normal coronary arteries isn't frequent. The aim of this study is to describe clinical characteristic and mid-term follow-up of those patients.

PATIENTS AND METHOD

Between January 1997 and December 2004 we identified 75 patients with MI and normal coronary arteries in a coronary angiography performed within one month of the AMI. All had criteria of MI and their coronary arteries were smooth and without obstructive lesions.

RESULTS

The incidence was 3%, and mean age (standard deviation): 49 (11) years; 63% of patients were males and 47% were smokers, 33% had hypertension, 24% dislipemia and 9% diabetes. No patient had previous angina. MI location was anterior in 43%, inferior in 40% and lateral in 17%. The peak of creatine phosphokinase was 700 U/dl (range: 431-1,115) and the ejection fraction was 65% (14%). After a medium follow up of 30 months (range: 12-84) the events were: one death and 2 new MI.

CONCLUSIONS

MI with normal coronary arteries is rare, is associated with a relative low rate of coronary risk factors, and with a good initial outcome, low rate of recurrent events and preservation of left ventricular function.

Myocardial infarction with normal coronary arteries: a conundrum with multiple aetiologies and variable prognosis: an update

The existence of myocardial infarction despite angiographically normal coronary arteries was recognized more than 30 years ago. Since then, various series of such patients have been described, but the aetiology and pathogenesis of the condition are still a source of debate. Evidence exists for a role of coronary vasospasm, thrombosis, embolization and inflammation, per se or combined, in determining the occurrence of myocardial infarction in the presence of angiographically normal coronary arteries. Endothelial dysfunction, possibly superimposed to nonangiographically evident atherosclerosis, may be an underlying common feature predisposing to the acute event. Additionally, myocarditis may explain some of these occurrences. Myocardial infarction with normal coronary arteries is therefore likely the result of multiple pathogenetic mechanisms. Although most reports emphasize the good prognosis of this condition, in general much better than myocardial infarction with coronary artery disease, prognosis is likely variable according to the underlying mechanism. This review summarizes current knowledge on this condition and examines areas of recent progress.

Clinical characteristics and mid-term prognosis of acute coronary syndrome in HIV-infected patients on antiretroviral therapy

OBJECTIVES

Acute coronary syndromes (ACSs) and coronary artery disease are emerging complications in HIV-infected patients on highly active antiretroviral treatment. The aim of this study was to determine the mid-term prognosis of ACS in HIV-infected patients.

METHODS

We evaluated the clinical characteristics and follow-up profile [38+/-15 months; mean+/-standard deviation (SD)] of ACS in 20 HIV-infected patients (mean +/-SD: age 44+/-8 years; range 35-65 years). All had coronary angiograms performed mean time 3+/-48 h after the onset of symptoms.

RESULTS

Eighteen patients were on antiretroviral therapy, of whom 13 patients were on regimens including protease inhibitors (mean duration+/-SD: 19+/-13 months). Fifteen patients had a first episode of ST segment elevation ACS and five had non-ST segment elevation ACS. Tobacco consumption (80%) and hypercholesterolaemia (50%) were the most frequent cardiovascular risk factors. During initial hospitalization, four patients were treated with thrombolysis, two had primary coronary angioplasty and seven had secondary coronary angioplasty. At follow up, 10 patients (50%) had had 18 cardiovascular events: one cardiovascular death, seven episodes of recurrent myocardial ischaemia in four patients, three pulmonary oedemas in two patients, and seven revascularization procedures in five patients.

CONCLUSIONS

This preliminary report highlights the risk of ACS and related complications in HIV-infected patients and raises questions regarding the implications of antiretroviral treatment.

Normal angiogram in acute coronary syndrome-preangiographic risk stratification, angiographic findings and follow-up

BACKGROUND

Coronary angiographies performed during acute coronary syndrome show different coronary morphologies-vessel occlusions, thrombi and various types of stenoses. In a few cases of acute coronary syndrome, angiography reveals normal coronary arteries. It is the purpose of this study to analyze this specific subset of patients who presented with an acute coronary syndrome but had a normal coronary angiogram with respect to the preangiographic diagnostics, risk stratification and clinical follow-up.

METHODS AND RESULTS

A total of 897 coronary angiographies were performed as an emergency procedure in our institution. The majority of patients (n = 821) presented with coronary artery disease and the majority was treated by mechanical revascularization (86.3%). In 76 patients (8.5%), no coronary artery stenosis was documented. However, according to the preangiographic risk stratification, coronary artery disease was expected in these patients. Observations documented angiographically included coronary spasms (6.6%) and muscle bridges (5.3%). During a mean follow-up of 11.2 +/- 6.4 months, one patient developed an acute myocardial infarction requiring coronary intervention. All other patients were free of any cardiac event.

CONCLUSIONS

In summary, we have to consider that coronary angiography may not always detect the cause of myocardial ischemia in every patient. There is a small group of patients with normal coronary angiograms during acute coronary syndrome. Additional diagnostic procedures like intravascular ultrasound (IVUS) or the assessment of intracoronary physiological parameters may increase the diagnostic value of angiography.

Premature coronary artery disease: clinical risk factors and prognosis

Coronary artery disease (CAD) that becomes manifest in young adults can have devastating consequences. Additionally, the study of young patients with CAD may provide insight into the genetic basis of coronary disease. Over the past few years, our understanding of risk factors in this population has been expanded to include social, environmental, and emotional factors. The identification of genetic markers for disease is just beginning. Also, it has recently been shown that CAD in young adults has a poor long-term prognosis, meaning that clinicians caring for these patients must be aggressive in risk factor control.

Long-term prognosis of patients having acute myocardial infarction when </=40 years of age

Data on the long-term prognosis of acute myocardial infarction (AMI) in young patients are limited. This study investigated long-term survival and risk predictors in a series of 108 consecutive patients </=40 years old who represented 4% of 2,644 patients who presented with AMI at a single center between June 1986 and April 1992. Four patients died soon after admission. The overall mortality rate of the 104 survivors was 25.5% at 15 years. The mortality rate was higher in patients who had type 1 diabetes mellitus (p = 0.01), long-term excessive alcohol intake (p = 0.035), peripheral arterial disease (p = 0.004), previous AMI (p = 0.04), anterior AMI (p = 0.01), and depressed left ventricular ejection fraction (p <0.0001). Cumulative survival rates (Kaplan-Meier analysis) at 1, 5, 10, and 15 years were 99%, 95%, 86%, and 75%, respectively. Event-free survival rates (death, AMI, coronary intervention, severe angina pectoris, malignant arrhythmias, and congestive heart failure) at the same times were 88%, 76%, 60%, and 43%, respectively. The strongest independent predictors of the long-term mortality rate were ejection fraction </=45% (odds ratio 4.4, 95% confidence interval 1.6 to 12.4, p <0.001) and peripheral arterial disease (odds ratio 45.9, 95% confidence interval 3.79 to 555, p <0.0001). These data suggest that the long-term prognosis and functional status of young patients who have AMI are not benign, especially when ejection fraction is decreased or peripheral atherosclerotic disease is present.

Long-term follow-up of coronary artery disease presenting in young adults

OBJECTIVES

This study evaluated long-term survival and predictors of elevated risk for young adults diagnosed with coronary artery disease (CAD).

BACKGROUND

Coronary artery disease is rarely seen in young adults. Traditional cardiac risk factors have been studied in small series; however, many questions exist.

METHODS

We identified 843 patients under age 40 with CAD diagnosed by coronary angiography from 1975 to 1985. Death, hypertension, gender, family history, prior myocardial infarction (MI), diabetes, heart failure, angina class, number of diseased vessels, ejection fraction (EF), Q-wave infarction, in-hospital death, and initial therapy were studied. Patients were followed for 15 years.

RESULTS

The mean age was 35 for women (n = 94) and 36 for men (n = 729). The average EF was 55%. Fifty-eight percent of the subjects had single-vessel disease, and 10% were diabetic. The strongest predictors of long-term mortality were a prior MI (hazard ratio [HR] 1.32, 95% confidence interval [CI] 1.00 to 1.73), New York Heart Association class II heart failure (HR 1.75, 95% CI 1.03 to 2.97), and active tobacco use (HR 1.59, 95% CI 1.14 to 2.21). Revascularization, rather than medical therapy, was associated with lower mortality (coronary angioplasty: HR 0.51, 95% CI 0.32 to 0.81; coronary artery bypass graft: HR 0.68, 95% CI 0.50 to 0.94). Overall mortality was 30% at 15 years. Patients with diabetes had 15-year mortality of 65%. Those with prior MI had 15-year mortality of 45%, and patients with an EF <30% a mortality of 83% at 15 years.

CONCLUSIONS

Coronary disease in young adults can carry a poor long-term prognosis. A prior MI, diabetes, active tobacco abuse, and lower EF predict a significantly higher mortality.

Black-white differences in severity of coronary artery disease among individuals with acute coronary syndromes

OBJECTIVE

To determine whether the extent of coronary obstructive disease is similar among black and white patients with acute coronary syndromes.

DESIGN

Retrospective chart review.

PATIENTS

We used administrative discharge data to identify white and black male patients, 30 years of age or older, who were discharged between October 1, 1989 and September 30, 1995 from 1 of 6 Department of Veterans Affairs (VA) hospitals with a primary diagnosis of acute myocardial infarction (AMI) or unstable angina (UnA) and who underwent coronary angiography during the admission. We excluded patients if they did not meet standard clinical criteria for AMI or UnA or if they had had prior percutaneous transluminal coronary angioplasty or coronary artery bypass grafting.

MEASUREMENTS AND MAIN RESULTS

Physician reviewers classified the degree of coronary obstruction from blinded coronary angiography reports. Obstruction was considered significant if there was at least 50% obstruction of the left main coronary artery, or if there was 70% obstruction in 1 of the 3 major epicardial vessels or their main branches. Of the 628 eligible patients, 300 (48%) had AMI. Among patients with AMI, blacks were more likely than whites to have no significant coronary obstructions (28/145, or 19%, vs 10/155 or 7%, P =.001). Similarly, among patients with UnA, 33% (56/168) of blacks but just 17% (27/160) of whites had no significant stenoses (P =.012). There were no racial differences in severity of coronary disease among veterans with at least 1 significant obstruction. Racial differences in coronary obstructions remained after correcting for coronary disease risk factors and characteristics of the AMI.

CONCLUSIONS

Black veterans who present with acute coronary insufficiency are less likely than whites to have significant coronary obstruction. Current understanding of coronary disease does not provide an explanation for these differences.

Acute myocardial infarction with angiographically normal coronary arteries

The exact etiology of myocardial infarction remains unknown in a majority of the patients with normal coronary arteries. Those who smoke cigarettes and use cocaine are more prone to have this condition. The possible mechanisms underlying myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism, an imbalance between oxygen demand and supply, nonatherosclerotic coronary diseases, coronary trauma, coronary vasospasm, and coronary thrombosis. Myocardial infarction with normal coronary arteries primarily affects younger persons and is distinctly rare in patients older than 50 years. We describe a case of acute myocardial infarction with normal coronary arteries in a 61-year-old woman who smoked cigarettes. The clinical perspectives and management of the myocardial infarction with normal coronary arteries are discussed.

Characteristics and prognosis of myocardial infarction in patients with normal coronary arteries

STUDY OBJECTIVES

Myocardial infarction with angiographically normal coronary arteries (MINC) is a life-threatening event with many open questions for physicians and patients. There are little data concerning the prognosis for patients with MINC.

DESIGN

Retrospective follow-up study.

SETTING

Tertiary referral center.

PATIENTS

Patients with MINC were investigated and compared to age- and sex-matched control subjects with myocardial infarction due to coronary artery disease (CAD). The patients were examined clinically using stress exercise and hyperventilation tests. Migraine and Raynaud's symptoms were determined by means of a standardized questionnaire. Serum lipoproteins; the seroprevalence of cytomegalovirus, Helicobacter pylori, and Chlamydia pneumoniae infections; and the most frequent causes of thrombophilia were assessed.

MEASUREMENTS AND RESULTS

From > 4,300 angiographies that were performed between 1989 and 1996, 21 patients with MINC were identified. The mean +/- SD patient age at the time of myocardial infarction was 42 +/- 7.5 years. When compared to control subjects (n = 21), patients with MINC had fewer risk factors for CAD. In contrast, MINC patients had more frequent febrile reactions prior to myocardial infarction (six patients vs zero patients; p < 0.05), and the migraine score was significantly higher (7.1 +/- 6.3 vs 2.2 +/- 4.1; p < 0.01). The seroprevalence of antibodies against cytomegalovirus, C pneumoniae, and H pylori tended to be higher in patients with MINC and CAD as compared to matched healthy control subjects. Three patients with MINC vs none with CAD had coagulopathy. During follow-up (53 +/- 37 months), no major cardiac event occurred in the MINC group; no patients with MINC vs nine with CAD (p = 0.0001) underwent repeated angiography.

CONCLUSION

High migraine score and prior febrile infection together with a lower cardiovascular risk profile are compatible with an inflammatory and a vasomotor component in the pathophysiology of the acute coronary event in MINC patients. The prognosis for these patients is excellent.

Myocardial infarction in young patients

Myocardial infarction in persons under the age of 45 years accounts for 6% to 10% of all myocardial infarctions in the United States. In this age group, it is predominantly a disease of men. Important risk factors include a family history of myocardial infarction before age 55 years, hyperlipidemia, smoking, and obesity. Unlike older patients, approximately half of young patients have single-vessel coronary disease, and in up to 20%, the cause is not related to atherosclerosis. Coronary angiography may be warranted in young patients with myocardial infarction to define the anatomy of the disease and to permit optimal management.

Clinical and angiographic features in patients under 35 years with a first Q wave acute myocardial infarction

Sixty patients less than 35 years with a first Q wave acute myocardial infarction were prospectively studied to evaluate their features, risk factors and evidence of any viral infection. Typical chest pain was present in 98.3% with Q waves and ST segment elevation in all. None had hypotension or cardiogenic shock. Smoking was the most common risk factor (81.7%). Mean total cholesterol was 5.74 (+/-1.42) mmol/l. History of a viral illness was present in 28.3%, severe emotional stress in 21.7% and exhausting physical activity in 18.3%. Mean left ventricular diastolic and end systolic volumes were increased (90.11+/-22.5 ml/m2) and (46.62+/-20.46 ml/m2), respectively. The ejection fraction was depressed (49.71+/-1.6%). Triple vessel disease was seen only in 6.8 and 26.7% had insignificant or no coronary artery disease. Left anterior descending artery was most frequently involved (66%). None had left main involvement. Coronary ectasia was present in 11.7%, intracoronary thrombus in 28.3% and 40% had collaterals. Patients with no significant disease had no diabetes, a smaller number had a raised total cholesterol or smoked and had a lower ejection fraction. Patients from the Indian subcontinent who had fewer conventional risk factors, had more severe disease than those from the Arab world suggesting that other etiological factors need investigation.