Right ventricular wall dissection complicating myocardial infarction.

Right ventricular wall dissection is extremely rare and can result in dismal clinical outcomes. We report a 68-year-old patient who presented with acute myocardial infarction and was found to have right ventricular wall dissection by ventriculography. At surgery, the infarcted myocardium was excised, and a two-patch technique was used to repair the ventricular septal defect.

Bivalirudin in percutaneous coronary intervention.

The chemistry and pharmacology, pharmacokinetics, pharmacodynamics, adverse effects, drug interactions, dosing and administration, and pharmacoeconomics of bivalirudin are reviewed; clinical trials of bivalirudin's application in percutaneous coronary intervention (PCI) are also discussed. Bivalirudin is a direct thrombin inhibitor approved for use in PCI. It reversibly binds to thrombin's catalytic site and substrate recognition site and blocks both circulating and fibrin-bound thrombin. Peak concentrations occur in less than 5 minutes after bolus-dose administration, and its half-life is approximately 25 minutes. It is primarily eliminated renally, and dosage reduction may be required in patients with severe renal dysfunction. Two clinical trials have demonstrated that bivalirudin is at least as effective as unfractionated heparin (UFH) in preventing ischemic complications in PCI. Other trials have shown that bivalirudin has beneficial ischemic and hemorrhagic outcomes in a more modern PCI setting (i.e., intracoronary stent placement, clopidogrel, and glycoprotein IIb/IIIa-receptor inhibitors). Bivalirudin combined with provisional glycoprotein IIb/IIIa inhibitors was noninferior to UFH with planned glycoprotein IIb/IIIa inhibitors and superior to UFH alone with respect to ischemic and hemorrhagic endopoints in PCI. Major bleeding with bivalirudin has occurred in approximately 3% of patients in clinical trials, and it is not known to have any interactions with the cytochrome P-450 isoenzyme system. The acquisition cost of bivalirudin in one study was less than the combination of UFH and glycoprotein IIb/IIIa inhibitors. Bivalirudin combined with provisional glycoprotein IIb/IIIa inhibitors appears to be an acceptable alternative to the standard of care and is superior to UFH alone in PCI.

The VIVA trial: Vascular endothelial growth factor in Ischemia for Vascular Angiogenesis.

BACKGROUND: Recombinant human vascular endothelial growth factor protein (rhVEGF) stimulates angiogenesis in animal models and was well tolerated in Phase I clinical trials. VIVA (Vascular endothelial growth factor in Ischemia for Vascular Angiogenesis) is a double-blind, placebo-controlled trial designed to evaluate the safety and efficacy of intracoronary and intravenous infusions of rhVEGF. METHODS AND RESULTS: A total of 178 patients with stable exertional angina, unsuitable for standard revascularization, were randomized to receive placebo, low-dose rhVEGF (17 ng x kg(-1) x min(-1)), or high-dose rhVEGF (50 ng x kg(-1) x min(-1)) by intracoronary infusion on day 0, followed by intravenous infusions on days 3, 6, and 9. Exercise treadmill tests, angina class, and quality of life assessments were performed at baseline, day 60, and day 120. Myocardial perfusion imaging was performed at baseline and day 60. At day 60, the change in exercise treadmill test (ETT) time from baseline was not different between groups (placebo, +48 seconds; low dose, +30 seconds; high dose, +30 seconds). Angina class and quality of life were significantly improved within each group, with no difference between groups. By day 120, placebo-treated patients demonstrated reduced benefit in all three measures, with no significant difference compared with low-dose rhVEGF. In contrast, high-dose rhVEGF resulted in significant improvement in angina class (P=0.05) and nonsignificant trends in ETT time (P=0.15) and angina frequency (P=0.09) as compared with placebo. CONCLUSIONS: rhVEGF seems to be safe and well tolerated. rhVEGF offered no improvement beyond placebo in all measurements by day 60. By day 120, high-dose rhVEGF resulted in significant improvement in angina and favorable trends in ETT time and angina frequency.

Underutilization of evidence-based medications in acute ST elevation myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) 9 Registry.

The TIMI 9 Registry set out to assess the management strategies and outcomes of an unselected group of patients with acute myocardial infarction presenting with ST segment elevation (STEMI). Demographic, procedural, and outcome data were collected from 840 consecutive patients with STEMI at 20 hospitals in United States and Canada between February and September 1994. Of them, 60% were treated with thrombolytic therapy, 9% with primary angioplasty, and 31% did not receive reperfusion therapy. Patients who did not receive reperfusion therapy were older, more likely female, and had a higher prevalence of prior myocardial infarction, congestive heart failure, higher Killip class on admission, and longer time from onset of symptoms to presentation. In evaluating the standard contraindications for fibrinolysis, approximately 10% in the thrombolytic group, 40% in the primary percutaneous coronary intervention (PCI), and 34% of those not receiving reperfusion therapy had at least one of these characteristics. Of those patients treated with fibrinolysis, only 20% met the National Heart Attack Alert Program goal of door-to-drug time < or =30 minutes. Likewise, of those treated with primary PCI, only 30% had PCI performed within < or =90 minutes. In-hospital mortality was significantly higher for patients not treated with reperfusion therapy (18.9%), compared with patients treated with fibrinolysis (7.6%) and those treated with primary PCI (10.5%) (P < 0.001). Thus, we found that reperfusion therapy was underused, with only 69% of patients with STEMI receiving this proven treatment, and of those only 25% treated within the recommended timeline. These data suggest that there is room for improvement in the management of these patients.