Asymptomatic spontaneous coronary artery dissection.

Spontaneous coronary artery dissection (SCAD) is a rare cause of myocardial ischemia that could present as angina, acute myocardial infarction, or even sudden death. It occurs more commonly in women and it has been associated with autoimmune and collagen vascular diseases. The management and prognosis in these patients depend on the initial clinical presentation and the extent of dissection. In this article, we report 2 cases of asymptomatic SCAD that were diagnosed on routine preoperative evaluation. The management options and clinical implications are discussed.

The I allele of the angiotensin converting enzyme I/D polymorphism confers protection against coronary artery disease.

BACKGROUND: Mutations in genes regulating lipid metabolism, vasoactivity, and coagulation are important modulators of coronary artery disease (CAD). OBJECTIVE: This study investigated the association between allelic variants of the angiotensin converting enzyme (ACE), methytetrahydrofolate reductase, plasminogen activator inhibitor-1 and factor V genes and CAD. METHODS: Clinical, biochemical, and angiographic information were collected from 300 patients who underwent cardiac catheterization and their DNA was genotyped by restriction fragment length polymorphism. RESULTS: The frequency of the D allele of the ACE gene was significantly higher than the I allele in patients with more than 70% stenosis in any vessel. Among patients with more than 70% stenosis, carriers of the D allele were 2.8 times more likely to be males. The presence of the ACE I allele was negatively associated with CAD with (P=0.02 ,OR=0.38.) CONCLUSION: This study describes a protective role of the ACE I allele in individuals who may be at risk of developing CAD.

Cardiac tamponade caused by polymicrobial gram-negative organisms.

Polymicrobial gram-negative pericarditis is a rare entity. We describe the first case of suppurative pericarditis with Citrobacter diversus and Proteus mirabilis.

Comparison of the systemic levels of inflammatory markers after percutaneous coronary intervention with bare metal versus sirolimus-eluting stents.

BACKGROUND: Percutaneous coronary intervention (PCI) with bare metal stent (BMS) deployment causes plaque disruption and a rise in systemic levels of C-reactive protein (CRP), interleukin (IL)-6, and monocyte chemoattractant protein (MCP)-1. Our aim is to study whether PCI with sirolimus-eluting stent (SES) use attenuates this response. METHODS: Patients with stable angina undergoing single-vessel PCI were enrolled in a randomized, open-label fashion into a BMS group or an SES group. Blood samples were drawn pre-PCI, 24 hours post-PCI, and 30 days post-PCI. Systemic concentrations of CRP, IL-6, and MCP-1 were measured at all time points. RESULTS: In total, 41 patients were enrolled (21 in the BMS group and 20 in the SES group). The baseline plasma concentrations of all markers were comparable between groups. At 24 hours, the mean plasma CRP concentration in the SES group was 20.21 mg/dL versus 8.95 mg/dL in the BMS group (P = 0.15). The mean plasma IL-6 concentration at 24 hours was 25.41 pg/mL in the SES group versus 17.44 pg/mL in the BMS group (P = 0.17). The mean plasma MCP-1 concentration at 24 hours was 382.38 pg/mL in the SES group versus 329.04 pg/mL in the BMS group (P = 0.2). At 30 days, plasma concentrations of all three markers decreased to similar values between groups. CONCLUSIONS: The use of SES did not inhibit the rise in systemic concentrations of CRP, IL-6, and MCP-1 at 24 hours or 30 days post-PCI, compared with BMS. Moreover, at 24 hours, there was a trend for higher systemic levels of all proinflammatory markers in the SES group compared with the BMS cohort.

Split right coronary artery: its definition and its territory.

We report here, for perhaps the 1st time in the English-language literature, the extent of the territory fed by the anterior bifurcation of the (anomalous) split right coronary artery (RCA). A 64-year-old man presented with an occlusion of the anterior bifurcation of a split RCA--which resulted in an infarct that involved both the inferoseptal left ventricular wall and the anterior right ventricular free wall. Split RCA is the same anomaly as the improperly named "double right coronary artery." In reality, there are not 2 RCAs, but only split portions of the posterior descending branch of the RCA, with 2 separate proximal courses.

A young female with an unusual cause of dyspnea.

Within the context of coronary artery anomalies, coronary fistulas are classified by termination. A coronary artery fistula (CAF) involves a sizable communication between a coronary artery and a heart chamber (coronary-cameral fistula) or a segment of the systemic or pulmonary system (coronary artery arteriovenous fistula). These are often due to deviations from normal embryological development. CAF may be present in patients at any age, but is usually suspected in early childhood and accounts for 0.08-0.4% of congenital cardiac anomalies. They may also be acquired by trauma or from invasive cardiac procedures. The majority of CAF arises from the right coronary artery (55%) and the left anterior descending coronary artery, with the circumflex rarely involved. The outcome of these connections depends upon the termination site. The pathophysiology of these lesions is identical. Coronary artery anomalies are difficult to detect clinically. Most are benign but some may produce symptoms that can be life threatening. We present a female with an unusual cause of dyspnea found to have a continuous heart murmur, cardiac catheterization showed an evidence of a long tract arising from the origin of the right coronary artery with flow directed towards the right atrium and the right atrial appendage.

Prevalence of coronary artery calcium among asymptomatic men and women in a developing country: comparison with the USA data.

BACKGROUND: Coronary artery calcium score (CACS) correlates with atherosclerotic burden and predicts cardiac events. Most of the published data have been derived from the USA population. OBJECTIVE: To study the prevalence of coronary calcium in an asymptomatic population from the eastern Mediterranean region and compare it to data obtained from a large population study in the USA. RESULTS: A total of 1154 asymptomatic men and women from Lebanon underwent EBCT screening because of the presence of one or more CAD risk factors. Mean CACS as well as the percentile cut-points increased consistently with increasing age and, except for those above 74 years of age, were higher in men than women in each age stratum. Age, hypercholesterolemia, diabetes and smoking showed significant associations with CACS in men, while only age and hypercholesterolemia were significantly associated with CACS in women. Among men, the 75th and 90th percentile distributions were comparable to what is observed in developed countries such as the USA. CONCLUSION: Findings, from this first study in the region, suggest that despite a higher rate of diabetes and smokers in our study population, the CACS distribution in Lebanon is similar to that observed in the USA.

Acute myocardial infarction: clinical characteristics, management and outcome in a university medical centre in a developing Middle Eastern country.

BACKGROUND: The management and outcome of acute myocardial infarction (AMI) have not been well studied in developing countries, although demographic data from the World Health Organization indicate that developing countries contribute a major share to the global burden of cardiovascular disease. OBJECTIVES: To analyze the clinical characteristics, management and outcome of patients hospitalized with AMI in a university medical centre in a developing Middle Eastern country. METHODS: The study population comprised all patients hospitalized with AMI at the American University of Beirut between January 1, 1997, and December 30, 1998. The medical records of the patients were reviewed to determine their clinical characteristics, the diagnostic and invasive procedures used during the hospitalization, and any in-hospital complications, including death. RESULTS: The population comprised 184 patients with a mean age of 60+/-13 years. Fifty-two per cent of the infarcts were anterior and 76% developed Q waves. Fifty-one per cent of the patients received thrombolytic therapy. At discharge, 80% of the patients were given acetylsalicylic acid, 35% were given beta-blockers, 34% were given angiotensin-converting enzyme inhibitors and 30% were given statins. Seventy-two per cent of the patients underwent coronary angiography, 23% underwent percutaneous transluminal coronary angioplasty and 13% had coronary artery bypass grafting. The in-hospital mortality was 13%. The predictors of in-hospital mortality were advanced age (over 60 years), diabetes, prior AMI, Killip class greater than I and ejection fraction less that 40%. In contrast, the predictors of coronary angiography were younger age (less than 60 years), absence of diabetes or no history of AMI, Killip class I and ejection fraction greater than 40%. CONCLUSIONS: Coronary angiography after AMI was performed more frequently than expected in a university medical centre in a developing country, and it seemed to be selectively used in the low- risk patients rather than the high-risk ones. Furthermore, the underuse of medical therapy with beta-blockers and statins was evident. These findings should prompt cardiac societies in these countries to initiate educational campaigns focusing on the cost-effectiveness of therapy in AMI to optimize the use of their limited resources.

Analysis of referral patterns, predictive accuracy, and impact on patient management of myocardial perfusion imaging in a new nuclear cardiology laboratory.

BACKGROUND: Most of the published data on myocardial perfusion imaging (MPI) come from large tertiary-referral medical centers with extensive experience in cardiac imaging as well as a large volume of procedures. Whether the results of MPI remain as reliable in new nuclear cardiology laboratories with smaller volumes of procedures is unknown. The purpose of this study was to analyze the referral patterns, predictive accuracy, and impact of MPI on clinical practice in a newly opened nuclear cardiology laboratory. METHODS AND RESULTS: We performed a prospective study on all patients referred for MPI at our nuclear cardiology laboratory during its first year of operation. Patients were followed up for 3 months after the MPI study to determine whether they underwent coronary angiography. The study population consisted of 334 patients. Their mean age was 56 +/- 10 years, and 80% were men. Of the patients, 30% were asymptomatic, 29% had angina, and only 6% had recent acute myocardial infarction or unstable angina. Fifty-one patients (fifteen percent) were subsequently referred for coronary angiography. The positive and negative predictive values of MPI were 91% and 86%, respectively. The presence of reversible perfusion defects (P =.02) and the presence of multiple perfusion defects (P =.01) on MPI were the most important determinants of subsequent referral to coronary angiography. CONCLUSIONS: MPI stress testing retains its high diagnostic accuracy in a new nuclear cardiology laboratory with a relatively small volume of procedures. Furthermore, MPI findings in this population had a strong impact on the clinical practice of the referring physicians in terms of subsequent referral to coronary angiography.