Incidence of aspirin resistance is higher in patients with acute coronary syndrome and atrial fibrillation than without atrial fibrillation

SUMMARY In patients with atrial fibrillation, standard anticoagulation with a vitamin K antagonist plus dual antiplatelet therapy with a P2Y12 inhibitor and aspirin is the standard of care after percutaneous coronary intervention (PCI). While this therapy reduces the risk of thrombosis and stroke, it increases the risk of bleeding. It is unclear whether the antiplatelet effect of aspirin and clopidogrel may worsen atrial fibrillation (AF). OBJECTIVE Thus we aimed to analyze platelet aspirin resistance (AR) and clopidogrel resistance (CR) in acute coronary (ACS) patients based on sinus rhythm (SR) and AF. METHODS In this prospective trial, we included 543 patients (mean age: 62± 12 years; range: 26 - 89 years) who were on aspirin and clopidogrel therapy after the diagnosis of acute coronary syndrome. AR and CR were analyzed by a Multiplate® MP-0120 device by using the method of whole blood aggregometry. RESULTS AF patients had significantly higher age, mean platelet volume, and High-Sensitivity C-Reactive Protein (p< 0.01 for each parameter). Similarly, Arachidonic-acid induced (ASPI) aggregation was higher in AF patients compared to SR patients (666±218 vs. 187±179, p<0.001). Among the ACS patients, significantly more female patients had AF (p<0.001). The incidence of hypertension in the AF group was higher compared to the SR group (p<0.001). However, adenosine diphosphate levels were not at a significant level in the two groups. CONCLUSION Our findings indicate that the platelet inhibitory effect of Aspirin was worse for patients with AF, suggesting that the effectiveness of aspirin may be less in the prophylaxis of thromboembolism and more a bleeding risk.

RESUMO Em pacientes com fibrilação atrial, a anticoagulação padrão com antagonista da vitamina K mais terapia antiplaquetária dupla (DAPT) com inibidor de P2Y12 e aspirina é o padrão de tratamento após intervenção coronária percutânea (ICP). Enquanto essa terapia reduz o risco de trombose e derrame, aumenta o risco de sangramento. Não está claro se o efeito antiplaquetário da aspirina e do clopidogrel pode piorar a fibrilação atrial (FA). OBJETIVO Analisar a resistência à aspirina plaquetária (AR) e ao clopidogrel (CR) em pacientes coronarianos agudos (SCA) com base no ritmo sinusal (SR) e na FA. MÉTODOS Neste estudo prospectivo, foram incluídos 543 pacientes (idade média: 62±12 anos; intervalo: 26-89 anos) em uso de aspirina e clopidogrel após o diagnóstico de síndrome coronariana aguda. AR e CR foram analisados por um dispositivo Multiplate® MP-0120, utilizando o método de agregometria de sangue total. RESULTADOS Os pacientes com FA apresentaram valores significativamente maiores para idade, volume médio de plaquetas e proteína C reativa de alta sensibilidade (p<0,01 para cada parâmetro). Da mesma forma, a agregação induzida por ácido araquidônico (Aspi) foi maior nos pacientes com FA em comparação com os pacientes com SR (666±218 vs. 187±179, p<0,001). Entre os pacientes com SCA, significativamente mais pacientes do sexo feminino apresentaram FA (p<0,001). A incidência de hipertensão no grupo FA foi maior em comparação com o grupo SR (p<0,001). No entanto, os níveis de difosfato de adenosina não foram expressivamente significativos nos dois grupos. CONCLUSÃO Nossos achados indicam que o efeito inibitório plaquetário da aspirina foi pior em pacientes com FA, sugerindo que a eficácia da aspirina pode ser menor na profilaxia do tromboembolismo, com maior risco de sangramento.

The relationship between mitral annular calcification, metabolic syndrome and thromboembolic risk

Abstract Introduction: Metabolic syndrome (MetS) is defined as an association between diabetes, hypertension, obesity and dyslipidemia and an increased risk of cardiovascular disease. Mitral annular calcification (MAC) is associated with several cardiovascular disorders, including coronary artery disease, atrial fibrillation (AF), heart failure, ischemic stroke and increased mortality. The CHA2DS2-VASc score is used to estimate thromboembolic risk in AF. However, the association among MAC, MetS and thromboembolic risk is unknown and was evaluated in the current study. Methods: The study group consisted of 94 patients with MAC and 86 patients with MetS. Patients were divided into two groups: those with and those without MAC. Results: Patients with MAC had a higher MetS rate (P<0.001). In patients with MAC, the CHA2DS2-VASc scores and the rate of cerebrovascular accident and AF were significantly higher compared to those without MAC (P<0.001, for both parameters). The results of the multivariate regression analysis showed that history of smoking, presence of MetS and high CHA2DS2-VASc scores were associated with the development of MAC. ROC curve analyses showed that CHA2DS2-VASc scores were significant predictors for MAC (C-statistic: 0.78; 95% CI: 0.706-0.855, P<0.001). Correlation analysis indicated that MAC was positively correlated with the presence of MetS and CHA2DS2-VASc score (P=0.001, r=0.264; P<0.001, r=0.490). Conclusion: We have shown that CHA2DS2-VASc score and presence of MetS rates were significantly higher in patients with MAC compared without MAC. Presence of MAC was correlated with CHA2DS2-VASc score, presence of MetS, AF and left atrial diameter and negatively correlated with left ventricular ejection fraction.

The CHA2DS2-VASc score for predicting atrial fibrillation in patients presenting with ST elevation myocardial infarction: prospective observational study

ABSTRACT BACKGROUND: Atrial fibrillation (AF) is the most common form of supraventricular arrhythmia following ST-elevation myocardial infarction (STEMI). The CHA2DS2-VASc and CHADS2 scores are used to estimate thromboembolic risk in cases of AF. Their usefulness in predicting the development of AF in patients presenting STEMI is unknown. OBJECTIVE: To evaluate the predictive value of the CHADS2 and CHA2DS2-VASc scores in patients with AF following STEMI. DESIGN AND SETTING: This prospective cohort study on 696 patients with STEMI was conducted at a tertiary-level cardiology clinic in a public university hospital. METHODS: Models including clinical and laboratory parameters were constructed to test the predictive value of CHADS2 and CHA2DS2-VASc scores. Patients were divided into two groups: with and without AF. Predictors of AF were determined using multivariate regression analysis. RESULTS: In the patients with AF, CHADS2 and CHA2DS2-VASc scores were significantly higher than in those without AF (for both P < 0.001). Factors associated with AF in multivariate analyses included CHA2DS2-VASc score (odds ratio, OR: 1.48; 95% confidence interval, CI: 1.25-1.75; P < 0.001), peak creatine kinase-myocardial binding (OR: 1.002; 95% CI: 1.00-1.003; P = 0.0024), duration of the coronary intensive care unit stay (OR: 1.69; 95% CI: 1.24-12.30; P = 0.001) and no use of renin-angiotensin system blockers (OR: 2.16; 95% CI: 1.14-4.10; P = 0.0017). Receiver operating characteristic curve analyses showed that CHA2DS2-VASc scores were significant predictors for new-onset AF (C-statistic: 0.698; 95% CI: 0.631-0.765; P < 0.001). CONCLUSION: CHADS2 and CHA2DS2-VASc scores predicted new AF in patients presenting STEMI.