NEW YORK (Reuters Health) – Manual thrombus aspiration during primary percutaneous coronary intervention (PCI) improves myocardial reperfusion and reduces final infarct size in patients with ST-segment elevation myocardial infarction (STEMI), results of a European study indicate.

“Thrombectomy prevents thrombus embolization and preserves microvascular integrity reducing infarct size, and it therefore represents a useful adjunctive therapy in primary PCI,” conclude the researchers in the January 27th issue of the Journal of the American College of Cardiology.

In the study, Dr. Gennaro Sardella of “Sapienza” University of Rome and colleagues randomly assigned 175 patients with STEMI to standard PCI or to manual intracoronary aspiration thrombectomy using the Export Medtronic thrombectomy device.

The primary study end points — myocardial blush grade of at least 2, and rate of 90-minute ST-segment elevation resolution above 70% — occurred more often in the thrombus-aspiration group than the standard PCI group (88% vs 60%, and 64% vs 39%, respectively; p = 0.001 for both), according to the article.

In a subset of 75 patients with anterior STEMI, Dr. Sardella’s team performed contrast-enhanced magnetic resonance imaging, which showed that in the acute phase, the extent of microvascular obstruction after recanalization was significantly lower in the thrombus-aspiration arm, and at 3 months, infarct size was significantly reduced only in the thrombus-aspiration arm.

“To our knowledge, this is the first study evaluating the effects of thrombectomy on microvascular obstruction and infarct size using contrast-enhanced MRI,” the investigators note.

They also observed lower rates of cardiac death at 9 months in the thrombus-aspiration group than the standard PCI group (4.6% vs 0%; p = 0.02).

J Am Coll Cardiol 2009;53:309-315.