Aspiration thrombectomy failed to decrease microvascular obstruction in non-STEMI patients

SAN FRANCISCO — Compared with PCI alone, aspiration thrombectomy did not reduce the extent of microvascular obstruction or improve clinical outcomes in patients with non-STEMI and thrombus-containing lesions.

In the prospective, multicenter TATORT-NSTEMI trial, Holger Thiele, MD, who presented data from the late-breaking study at TCT 2013, and colleagues randomly assigned 440 patients with non-STEMI to standard PCI (n=219) or PCI with adjunctive aspiration thrombectomy (n=221). All participants had ischemic symptoms within 72 hours of randomization and elevated cardiac troponin T or troponin I levels at 24 and 48 hours after the procedure.

The primary endpoint was microvascular obstruction from days 1 to 4 post-procedure as indicated by cardiac magnetic resonance.

Thrombectomy resulted in aspiration of thrombus material in 74% of recipients. Myocardial obstruction occurred in 30.8% of the thrombectomy group and 29.2% of the standard PCI group (P=.74). The extent of obstruction within the left ventricle did not differ significantly between groups, with a median of 1.95% (interquartile range [IQR]=0.8-4.1) in the thrombectomy group and 1.4% (IQR=0.7-2.6) in the PCI group (P=.17).

Subgroup analysis indicated no significant difference between the two procedures in the extent of myocardial obstruction according to sex (men, P=.83 and women, P=.76), the presence of diabetes (diabetes, P=.92 and no diabetes, P=.7), TIMI thrombus grade severity (TIMI thrombus grade 2 to 4, P=.97 and TIMI thrombus grade 5, P=.64), pre-procedure TIMI flow (TIMI flow grade 0 to 1, P=.73 and for TIMI flow grade 2 to 3, P=.91) or the use of glycoprotein IIb or IIIa inhibitors (P=.2 for use and P=.46 for nonuse).

Secondary endpoints included infarct size, myocardial salvage, post-procedural myocardial blush grade and TIMI flow, and enzymatic infarct size as indicated by troponin T at 24 and 48 hours post-procedure. The composite clinical endpoint included mortality, target vessel revascularization, congestive HF and reinfarction at 6 months post-procedure.

The two groups did not differ significantly with regard to any of the secondary endpoints, including myocardial blush grade (P=.63). Additionally, among 218 patients in the thrombectomy group and 216 patients in the PCI group with follow-up data at 6 months, the cumulative incidence of the composite clinical endpoint also did not differ significantly (P=.2).

“In this first randomized, multicenter trial in patients with NSTEMI with thrombus-containing lesions, aspiration thrombectomy led to aspiration of thrombus material in approximately 74% … which led us to a higher rate of primary stent implantation in these patients,” Thiele, deputy director of the University of Leipzig Heart Center in Germany, said at a press conference. “However, [thrombectomy] could not reduce the extent of microvascular obstruction … in comparison to standard PCI. These results are also supported by a lack of benefit in several of the secondary endpoints that we have assessed in this trial.”

For more information:

Thiele H. Session XVI: First report investigations II. Presented at: TCT 2013; Oct. 27-Nov. 1, San Francisco.

Disclosure: The study was funded through unrestricted grants from Lilly Germany and Terumo Europe. Thiele reports receiving research funding from Lilly, Maquet Cardiovascular, Medicines Company, Teleflex Medical and Terumo, and receiving speaker honoraria from AstraZeneca, Boehringer Ingelheim, Daiichi Sankyo, Lilly, Maquet Cardiovascular and Medicines Company.