Red versus white thrombi in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: clinical and angiographic outcomes.

BACKGROUND: Aspiration thrombectomy is used in primary percutaneous coronary interventions, but the importance of thrombus constituency has been scarcely investigated. The objective of this study was to evaluate thrombus constituency and its association with clinical, laboratory, and angiographic findings in patients with ST-segment elevation myocardial infarction. METHODS: From April 2010 to May 2011, 562 patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary interventions were considered for inclusion, and information on thrombi characteristics was available for 113 patients. Thrombus material were obtained and classified as white or red based on its constituency. Samples were analyzed by 3 independent pathologists blinded to clinical characteristics. RESULTS: The mean age of patients was 58.6 ± 12.7 years, and 69% were men. White thrombi were present in 31% of cases, and red thrombi, in 69%. Patients with white thrombi had smaller vessels and lower ischemic times. All other clinical, angiographic, and laboratory characteristics did not differ. White thrombi were smaller and associated with fibrin infiltration, whereas red thrombi were associated with red blood cell infiltration. Thirty-day death rates were lower in patients with white thrombi than red (0% vs 10.1%, respectively; P = .05), as were 30-day major adverse cardiac event rates (4.2% vs 13.9%; P = .10). Total ischemic time was well correlated with fibrin infiltration (R = -0.30; P < .01), red blood cell infiltration (R = 0.27; P < .01), and thrombus volume (R = 0.22; P = .02). CONCLUSIONS: White thrombi were present in one-third of cases and were associated with lower ischemic times, higher fibrin infiltration, smaller thrombus volume, and lower mortality. These findings suggest that thrombus constituency may be a useful prognostic tool in this setting.

Accuracy of dedicated risk scores in patients undergoing primary percutaneous coronary intervention in daily clinical practice.

BACKGROUND: Comparisons between dedicated risk scores in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) in real-world clinical practice are scarce. The aim of this study was to assess the diagnostic performance of the Global Registry of Acute Coronary Events (GRACE), Primary Angioplasty in Myocardial Infarction (PAMI), Thrombolysis in Myocardial Infarction (TIMI), and Zwolle scores in STEMI patients undergoing pPCI in contemporary clinical practice. METHODS: This was a prospective cohort study of consecutive patients with STEMI undergoing pPCI between December 2009 and November 2010 in a high-volume tertiary referral centre. The outcomes assessed were major cardiovascular events (MACEs) and death within 30 days. The diagnostic accuracy of the scores was assessed using receiver operating characteristic curves, and scores were compared using the DeLong method. RESULTS: During the study period, 501 patients were included. Within 30 days, 62 patients (12.4%) presented a MACE and 39 individuals (7.8%) died. All scores were statistically associated with death and MACE within 30 days (P < 0.01). The c-statistic and 95% confidence intervals for 30-day mortality were: GRACE, 0.84 (0.78-0.90); TIMI, 0.81 (0.74-0.87); Zwolle, 0.80 (0.73-0.87); and PAMI, 0.75 (0.68-0.82) (P < 0.01). There was no statistically significant difference regarding the accuracy of the TIMI, GRACE, and Zwolle scores for 30-day mortality, but the GRACE score was superior to the PAMI score (P < 0.01). CONCLUSIONS: The TIMI, GRACE, and Zwolle scores performed equally well as predictors of mortality in patients who underwent pPCI in current practice. These results suggest that these scores are suitable options for risk assessment in a real-world setting.

Preditores de insucesso de tromboaspiração em pacientes submetidos à intervenção coronária percutânea primária / Predictors of failed thrombus aspiration in patients undergoing primary percutaneous coronary intervention

INTRODUÇÃO: A tromboaspiração é recomendada como método adjunto à intervenção coronária percutânea (ICP) primária, mas o insucesso em recuperar trombos é relativamente frequente. O objetivo deste estudo foi avaliar as taxas de insucesso de tromboaspiração e identificar seus preditores, em uma série contemporânea de pacientes. MÉTODOS: Estudo de coorte prospectivo que incluiu pacientes consecutivos atendidos com infarto agudo do miocárdio com elevação do segmento ST e submetidos à ICP primária com tromboaspiração no período de dezembro de 2009 a dezembro de 2011. Os procedimentos de tromboaspiração foram realizados por decisão do operador, e o sucesso foi definido como aspiração efetiva de trombo pelo cateter dedicado, com recuperação do fluxo coronário (fluxo TIMI > 0). RESULTADOS: Foram realizadas 1.055 ICPs primárias, sendo que a tromboaspiração foi utilizada em 37% dos casos, com taxa de sucesso de 70%. Foram identificados 254 pacientes com sucesso e 107 com insucesso da tromboaspiração. Insucesso de tromboaspiração foi associado a: idade, hipertensão, diabetes mellitus, dislipidemia, ICP prévia, escore de risco TIMI, Killip IV, contagem de leucócitos, fibrinogênio sérico, diâmetro de referência do vaso-alvo e TIMI 3 pré-procedimento. Pacientes com insucesso da tromboaspiração apresentaram tendência a maior mortalidade (11,6% vs. 5,9%; P = 0,09). CONCLUSÕES: Insucesso de tromboaspiração durante ICP primária ocorreu em 30% dos casos e esteve associado a tendência de maior mortalidade. A identificação de preditores clínicos, laboratoriais e angiográficos pode auxiliar no aprimoramento desses dispositivos e em sua técnica, além da escolha de pacientes mais adequados para seu emprego.

BACKGROUND: Aspiration thrombectomy is recommended as an adjunctive method in patients undergoing primary percutaneous coronary intervention (PCI), however, thrombus aspiration failure is relatively frequent. The objective of this study was to evaluate the rate and identify predictors of failed thrombus aspiration in a contemporaneous series of patients. METHODS: Prospective cohort study including consecutive patients with acute ST-segment elevation myocardial infarction undergoing primary PCI with thrombus aspiration from December 2009 to December 2011. Aspiration thrombectomy was performed at the operator's discretion and success was defined as effective thrombus aspiration by a dedicated catheter with the achievement of a final TIMI flow > 0. RESULTS: 1,055 primary PCIs were performed and aspiration thrombectomy was used in 37% of cases with a success rate of 70%. Aspiration thrombectomy success was observed in 254 patients whereas failure was observed in 107 patients. Aspiration thrombectomy failure was associated with age, hypertension, diabetes mellitus, dyslipidemia, previous PCI, TIMI risk score, Killip IV, leukocyte count, serum fibrinogen, target vessel reference diameter and preprocedural TIMI 3 flow. Patients with failed thrombus aspiration had a trend towards higher mortality (11.6% vs. 5.9%; P = 0.09). CONCLUSIONS: Aspiration thrombectomy failure during primary PCI was observed in 30% of the cases and was associated with a trend towards higher mortality. The identification of clinical, laboratory and angiographic predictors may help improve these devices and the technique and enable better patient selection.