Invasive therapy superior to heparin in most patients with unstable CAD

August 27, 1999 Invasive therapy superior to heparin in most patients with unstable CAD WESTPORT, Aug 27 (Reuters Health) - Two reports published in the August 28th issue of The Lancet for the first time demonstrate the superiority of invasive over noninvasive strategies for treating most patients with unstable coronary artery disease. Nevertheless, they also show that heparin has a role to play in the early management of this disorder. "The early invasive approach should be the preferred strategy in most patients with unstable coronary-artery disease who have signs of ischemia on electrocardiography or raised biochemical markers of myocardial damage," Dr. Lars Wallentin, of University Hospital in Uppsala, Sweden, and other investigators in the FRISC II study conclude in the first of the reports. The study group randomized 2,457 patients with unstable coronary artery disease to either invasive treatment, with or without dalteparin, or to continued treatment with dalteparin without invasive treatments such as angioplasty or bypass surgery unless the patient's condition worsened. After 6 months, the incidence of the combined endpoint of death or myocardial infarction was significantly lower in the invasive treatment group than the noninvasive treatment group, at 9.4% and 12.1%, respectively. Invasive treatment also significantly reduced the risk of myocardial infarction alone, with a risk ratio of 0.77, and nonsignificantly reduced mortality alone, with a risk ratio of 0.65, the researchers report. In addition, patients treated invasively had half as many symptoms of angina and were half as likely to be readmitted compared with patients continued on dalteparin. "Dalteparin treatment provided no benefit when continued after revascularization," Dr. Wallentin and his team say. However, in the second article they show that dalteparin did appear to have a short-term benefit relative to placebo. In a separate study, the FRISC II group randomized 2,267 patients with unstable coronary artery disease to either dalteparin or placebo for 3 months, after open treatment for at least 5 days with dalteparin. At the end of therapy, patients using dalteparin had a significantly lower rate of death or myocardial infarction compared with controls, with rates of 6.7% and 8.0%, respectively. But these benefits were not observed at the 6-month follow-up visit. The FRISC II researchers suggest that "...in clinically stabilised patients with unstable coronary artery disease, the early protective effects of continued dalteparin treatment can be used to lower the risk for further cardiac events during the wait for an invasive assessment and, if appropriate, revascularization." In a Lancet editorial, Dr. J.-J. Goy, of University Hospital in Lausanne, Switzerland, comments that the appropriate treatment strategy for patients with unstable angina remains controversial, despite the new evidence reported in the same issue of the journal and elsewhere. Dr. Goy suggests that refined approaches to risk stratification in patients with unstable angina may be beneficial in determining which patients should be offered heparin treatment prior to invasive therapy and which would benefit more from immediate invasive intervention. Lancet 1999;354:694-695,701-715.