TOTAL Study Finds Routine Thrombectomy After STEMI May Increase Risk of Stroke

March 16, 2015—The TOTAL study was presented at the American College of Cardiology’s 64th annual scientific session in San Diego, California, and simultaneously published online in the New England Journal of Medicine. TOTAL, a randomized trial of routine aspiration thrombectomy with percutaneous coronary intervention (PCI), found that thrombectomy treatment appears to increase the risk of stroke without providing the intended benefit.

According to the ACC press release, the study was composed of more than 10,000 patients from 87 hospitals in 20 countries who were undergoing PCI in response to ST-segment elevation myocardial infarction (STEMI). The patients were randomly assigned (1:1) to receive PCI alone or PCI with manual thrombectomy. Mechanical thrombectomy was not tested.

At 6 months of follow-up, the investigators found no differences between the groups in terms of the study’s primary endpoint, a composite of the rates of cardiovascular death, subsequent heart attack, cardiogenic shock, and the most severe category of heart failure. Bailout thrombectomy was performed in 7% of the patients assigned to receive PCI alone.

In the ACC press release, the study’s lead investigator Sanjit Jolly, MD, commented, “The message from this study is that thrombectomy should not be used as a routine strategy. Given the downsides we observed, the findings suggest thrombectomy should be reserved as a bailout therapy to be used only when an initial angioplasty attempt fails to open up the artery.” Dr. Jolly is Associate Professor and interventional cardiologist at McMaster University in Hamilton, Ontario, Canada.

As summarized in the ACC announcement, the rate of cardiovascular death, subsequent heart attack, cardiogenic shock, and the most severe category of heart failure was 6.9% in the group receiving thrombectomy and 7% in the control group, a difference that was not statistically significant. In addition to revealing no differences in the composite primary endpoint or the individual components of this endpoint, the analysis also showed no significant differences in the study’s secondary endpoint, which included the primary endpoints plus stent thrombosis or the need for revascularization.

The TOTAL study showed a statistically significant increase in stroke in the thrombectomy group. Dr. Jolly noted that it is possible that removing a blood clot from the heart could increase the risk that the clot will be lost during the removal process and eventually travel to the brain, causing a stroke, but this explanation would likely apply only to strokes that occur soon after the procedure. The relatively small number of strokes observed in the study within 30 days—33 patients, or 0.7%, in the thrombectomy group and 16 patients, or 0.3%, in the control group—leaves open the possibility that the finding was due to chance alone.

The investigators found no difference in outcomes based on the size of the blood clots, despite previous speculation that the procedure might be particularly beneficial in patients with larger clots.

Dr. Jolly stated, “There are still open questions that aren’t resolved by our study, and this procedure could still be beneficial for a small subset of patients. Clearly, for patients who fail an initial angioplasty attempt, thrombectomy may be very important and is really the only way to open up the artery. We did not design the trial to test the effectiveness of selective or bailout thrombectomy.”

Previous smaller studies have suggested benefits of routine thrombectomy or showed mixed results, but these studies involved fewer patients and some were limited to a single hospital.

“Our findings illustrate the importance of doing large trials. There are many things in clinical practice that we believe are beneficial but need to be tested in large randomized trials. Only by doing this can we be certain of what helps patients and move the field forward,” concluded Dr. Jolly.