Presence of older thrombus is an independent predictor of long-term mortality in patients with ST-elevation myocardial infarction treated with thrombus aspiration during primary percutaneous coronary intervention.
BACKGROUND
Routine thrombus aspiration is frequently used during primary percutaneous coronary intervention in patients with ST-elevation myocardial infarction to prevent distal embolization. Recently, evidence of clinical benefit was published. In 50% of the ST-elevation myocardial infarction patients with an onset of symptoms <12 hours before, thrombi were shown to be >1 day old. This observation illustrates that plaque rupture and coronary occlusion are significantly separated in time. In the present study, we correlate the presence of fresh versus older thrombus with long-term mortality.


RESULTS
Thrombus aspiration was performed in 1315 patients treated with primary percutaneous coronary intervention with 3 devices (Rescue, Export, and Proxis). Aspirated material was fixed in formalin and processed for histopathology. If possible, thrombus age was classified as either fresh only (<1 day) or older (>1 day). We identified fresh thrombus in 552 patients and older thrombus in 372 patients. The cumulative Kaplan-Meier estimate of all-cause mortality at 4 years was significantly higher in patients with older thrombus (16.0%) compared with patients with fresh thrombus (7.4%), with a hazard ratio of 1.82 (95% confidence interval, 1.17 to 2.85; P=0.008). Multivariate analysis identified the presence of older thrombus, in addition to other established predictors, as an independent predictor (hazard ratio, 1.83; 95% confidence interval, 1.14 to 2.93; P=0.01) of long-term mortality.


CONCLUSIONS
Our study demonstrates that the presence of older thrombus, in addition to other established predictors, is an independent predictor of long-term mortality in patients with ST-elevation myocardial infarction treated with thrombus aspiration during primary percutaneous coronary intervention.
Department of Cardiology, B2-137, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands.
Miranda C A
MC
Kramer
Allard C
AC
van der Wal
Karel T
KT
Koch
Johanna P H M
JP
Ploegmakers
René J
RJ
van der Schaaf
José P S
JP
Henriques
Jan
J
Baan
Saskia Z H
SZ
Rittersma
Marije M
MM
Vis
Jan J
JJ
Piek
Jan G P
JG
Tijssen
Robbert J
RJ
de Winter
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000401:mortality*; D003328:Coronary Thrombosis / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D011237:Predictive Value of Tests; D012307:Risk Factors; D013396:Suction / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome