Manohar S. Gowda

Complementary roles of color-flow duplex imaging and intravascular ultrasound in the diagnosis of renal artery fibromuscular dysplasia

OBJECTIVES The purpose of this study was to compare color-flow duplex imaging (CFDI), intravascular ultrasound (IVUS), and renal arteriography in diagnosing renal artery (RA) fibromuscular dysplasia (FMD) and correlating with the hemodynamic response to balloon angioplasty (BA) in patients with drug-resistant hypertension. BACKGROUND Renal arteriography is generally regarded as the gold standard for diagnosing RA FMD. The observation that CFDI and IVUS depicted endoluminal abnormalities suggestive of RA FMD in some patients with normal renal arteriograms prompted comparison of these modalities in a consecutive series of patients. METHODS Twenty hypertensive patients with CFDI suggestive of RA FMD (mid-to-distal flow derangement and velocity augmentation) underwent renal arteriography, IVUS, and BA, with both immediate and long-term blood pressure (BP) response assessment. RESULTS All patients were women, aged 31 to 86 years (mean 62 years). On IVUS, various endoluminal defects (eccentric ridges; fluttering membranes; spiraling folds) were depicted at locations predicted by CFDI and were uniformly identified at sites where arteriography depicted classic evidence of FMD (8 patients). However, similar defects were detected by IVUS when angiography was borderline (7 patients) or normal (5 patients). Balloon angioplasty eliminated (16 patients) or reduced (4 patients) the IVUS findings and lowered systolic BP in all (mean reduction 53 mm Hg, p < 0.0001). This reduction was maintained during follow-up of 4 to 22 (mean 13) months (mean reduction 44 mm Hg, p < 0.0001), independent of baseline angiographic appearance. CONCLUSIONS Both CFDI and IVUS depict the blood flow and endoluminal abnormalities of RA FMD. Balloon angioplasty eliminates or improves IVUS findings and produces substantial, sustained BP reduction, an effect that is independent of baseline arteriographic appearance, calling into question the legitimacy of arteriography as the diagnostic gold standard.

Improving Death Certificate Completion: A Trial of Two Training Interventions

The death certificate is an important medical document that impacts mortality statistics and health care policy. Resident physician accuracy in completing death certificates is poor. We assessed the impact of two educational interventions on the quality of death certificate completion by resident physicians. Two-hundred and nineteen internal medicine residents were asked to complete a cause of death statement using a sample case of in-hospital death. Participants were randomized into one of two educational interventions: either an interactive workshop (group I) or provided with printed instruction material (group II). A total of 200 residents completed the study, with 100 in each group. At baseline, competency in death certificate completion was poor. Only 19% of residents achieved an optimal test score. Sixty percent erroneously identified a cardiac cause of death. The death certificate score improved significantly in both group I (14±6 vs 24±5, p<0.001) and group II (14±5 vs 19±5, p<0.001) postintervention from baseline. Group I had a higher degree of improvement than group II (24±5 vs 19±5, p<0.001). Resident physicians’ skills in death certificate completion can be improved with an educational intervention. An interactive workshop is a more effective intervention than a printed handout.

One-year outcomes of diabetic versus nondiabetic patients with non-Q-wave acute myocardial infarction treated with percutaneous transluminal coronary angioplasty.

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.

Incidence of Factor V Leiden in Patients with Acute Myocardial Infarction

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.

Differential Benefits and Outcomes of Tirofiban vs Abciximab for Acute Coronary Syndromes in Current Clinical Practice

Little comparative data exist for glycoprotein IIb/IIIa inhibitors in acute coronary syndromes (ACS). Two hundred twenty-eight patients were studied: 114 received tirofiban (TI) and 114 received abciximab (AB) for either unstable angina (UA) or myocardial infarction (MI). All patients received aspirin, heparin, and ticlopidine or clopidogrel. Baseline characteristics were similar between the 2 groups for admitting diagnosis (UA vs MI), age, gender, ejection fraction, diabetes mellitus, prior coronary artery disease, prior myocardial infarction (MI), prior bypass surgery, hypertension, congestive heart failure, hyperlipidemia, MI type (Q vs non-Q), or location. Drug administration time (mean) was 13 hours (AB) and 24 hours (TI). All AB was administered in the catheterization laboratory as compared to TI (34% in laboratory and 66% before laboratory). More AB patients received angioplasty or stent (92% vs 80%, p = 0.008) while more TI patients had CABG (10% vs 3%, p = 0.027). In-hospital complications including death, MI, urgent revascularization, cerebrovascular accidents or transient ischemic attacks, and access site bleeding were similar (p = NS). Multivariate predictors of events (odds ratios) were prior coronary artery bypass graft (2.3), diabetes (1.7), and prior percutaneous translu minal coronary angioplasty (1.7), but not the agent used. Over a mean follow-up of 13 months, the individual endpoints of death, MI, revascularization, or hospitalization were similar for both groups. The AB patients had improved freedom from revascularization (100% vs 81%, p=0.015) in an emergent setting and TI patients had improved freedom from revascularization (93% vs 77%, p= 0.038) with elective procedures. Tirofiban and abciximab appear effective and safe when used for ACS when recommended dosing and precautions are followed. Major adverse outcomes are rare and bleeding complications uncommon.