Increase in ticagrelor use over time is associated with lower rates of ischemic stroke following myocardial infarction

OBJECTIVES

To evaluate the impact of a rapid change in preferred treatment from clopidogrel to ticagrelor on the risk of ischemic stroke following acute myocardial infarction (AMI).

METHODS

Data for AMI patients treated with either clopidogrel or ticagrelor were obtained from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA). Patients were divided into two cohorts, each covering a two-year time period; the initial prescription of ticagrelor (20 Dec 2011) was used as a cut-off point. Patients in the early cohort (n = 23,447) were treated with clopidogrel, while those in the later cohort (n = 24,227), were treated with either clopidogrel (47.9%) or ticagrelor (52.1%). Kaplan-Meier analyses were used to assess the risk of ischemic stroke over time, with multivariable Cox regression analyses used to identify predictors of ischemic stroke.

RESULTS

Of 47,674 patients, there were 1203 cases of ischemic stroke. Cumulative Kaplan-Meier incidence estimates of ischemic stroke after one year were 2.8% vs. 2.4% for the early and late cohorts, respectively (p = 0.001). Older age, hypertension, diabetes, previous stroke, congestive heart failure, atrial fibrillation, and ST-elevation myocardial infarction were associated with an increased risk of ischemic stroke. Percutaneous coronary intervention and statins at discharge were associated with a decreased risk of ischemic stroke, as was higher estimated glomerular filtration rate. Membership of the late cohort correlated with a 13% reduction in the relative risk of ischemic stroke.

CONCLUSIONS

The introduction of ticagrelor as well as an improved management of AMI was associated with a lower rate of ischemic stroke in a relatively unselected AMI population.

Ischemic stroke rates decrease with increased ticagrelor use after acute myocardial infarction in patients treated with percutaneous coronary intervention

Aims

It is unknown whether dual antiplatelet therapy with ticagrelor instead of clopidogrel reduces the risk of ischaemic stroke in acute myocardial infarction patients that undergo percutaneous coronary intervention. This study investigated whether the introduction of dual antiplatelet therapy with ticagrelor was associated with reduced ischaemic stroke risk in a real-world population.

Methods and results

Patients with ischaemic stroke after acute myocardial infarction from 8 December 2009–31 December 2013 were identified using the Register for Information and Knowledge on Swedish Heart Intensive Care Admissions and the Swedish National Patient Register. The study period was divided into two similar periods using the date of the first prescription of ticagrelor as the cut-off. The risk of ischaemic stroke in percutaneous coronary intervention-treated acute myocardial infarction patients during the first period (100% clopidogrel treatment) versus the second period (60.7% ticagrelor treatment) was assessed using Kaplan-Meier analysis. Variables associated with ischaemic stroke were identified using a multivariable Cox proportional hazards model. There were 686 ischaemic stroke events (2.0%) among 34931 percutaneous coronary intervention-treated acute myocardial infarction patients within one year, 366 (2.2%) during the first period and 320 (1.8%) during the second period ( p = 0.004). The Cox model showed a 21% relative risk reduction in ischaemic stroke in the second period versus the first one (hazard ratio 0.79, 95% confidence interval, 0.68–0.92; p = 0.003). The independent predictors of increased stroke risk were older age, hypertension, diabetes mellitus, atrial fibrillation, heart failure during hospitalization, previous ischaemic stroke, and ST-segment elevation myocardial infarction.

Conclusion

The risk of ischaemic stroke in percutaneous coronary intervention-treated acute myocardial infarction patients decreased after the introduction of ticagrelor in Sweden.

The risk of ischemic stroke after an acute myocardial infarction in patients with decreased renal function

BACKGROUND

Data on the incidence, trends over time and predictors of ischemic stroke after an acute myocardial infarction (AMI) are sparse for patients with chronic kidney disease (CKD).

METHODS

Data for unselected AMI patients were obtained from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA) between 2003 and 2010. Patients with and without CKD were compared. Multiple logistic regression was performed to identify predictors of ischemic stroke during the hospitalization for AMI, Kaplan-Meier analysis was used to analyze the 1-year postdischarge ischemic stroke trends over time and Cox regression analysis was used to identify predictors.

RESULTS

Of 118,434 AMI patients, 40,679 had CKD. The CKD patients had more extensive previous cardiovascular disease and received less reperfusion and secondary preventive therapies than the patients without CKD. An inhospital ischemic stroke occurred in 2.3 and 1.2% of CKD and non-CKD patients, respectively. The incidence of ischemic stroke during hospitalization for AMI was stable during the study period. The occurrence of ischemic stroke after hospital discharge decreased between 2003-2004 and 2009-2010 from 4.1 to 2.5% in CKD patients and from 2.0 to 1.3% in non-CKD patients, respectively. Percutaneous coronary intervention (PCI) and statins were independently associated with a reduced risk of stroke after discharge from hospital.

CONCLUSIONS

Ischemic stroke is a more common complication after an AMI in CKD patients than in non-CKD patients, but the risk has decreased in recent years. The increased use of PCI and statins may have contributed to this reduction.

Mortality after ischemic stroke in patients with acute myocardial infarction: predictors and trends over time in Sweden

BACKGROUND AND PURPOSE

Acute myocardial infarction (AMI) increases the risk of ischemic stroke, and mortality among these patients is high. Here, we aimed to estimate the 1-year mortality reliably after AMI complicated by ischemic stroke. We also aimed to identify trends over time for mortality during 1998-2008, as well as factors that predicted increased or decreased mortality.

METHODS

Data for 173 233 unselected patients with AMI were collected from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions registry for 1998-2008. Specifically, we analyzed 1-year follow-up and mortality data for patients with AMI with and without ischemic stroke. Kaplan-Meyer analysis was used to analyze mortality trends over time, and Cox regression analysis was used to identify uni- and multivariate predictors of mortality.

RESULTS

The 1-year mortality was 36.5% for AMI complicated by ischemic stroke and 18.3% for AMI without stroke. Mortality decreased over time in patients with and without ischemic stroke. The absolute decreases in mortality were 9.4% and 7.5%, respectively. Reperfusion and secondary preventive therapies were associated with a decreased mortality rate.

CONCLUSIONS

Mortality after AMI complicated by an ischemic stroke is very high but decreased from 1998 to 2008. The increased use of evidence-based therapies explains the improved prognosis.

Dynamics of platelet activation in diabetic and non-diabetic subjects during the course of an acute myocardial infarction

INTRODUCTION

The dynamics of platelet activation during the course of a myocardial infarction is unknown but of great importance in terms of risk assessment and anti-thrombotic therapy. The aim of the present study was sequentially to analyse platelet activation in diabetic and non-diabetic subjects with an acute myocardial infarction.

MATERIALS AND METHODS

We used a sensitive laser light scattering technique to assess platelet aggregation as a measure of activation. Measurements were made on the first, second, third and fifth day in-hospital. Two hundred and forty-three patients with an acute myocardial infarction, of whom 48 had diabetes, were included.

RESULTS

Platelet activation increased until the third in-hospital day in both diabetic and non-diabetic subjects, despite intense anti-thrombotic therapy. The activation was more pronounced in diabetic subjects from the time of hospital admission. Platelet activation tended to decrease after the third in-hospital day.

CONCLUSIONS

We conclude that platelet activation increases rapidly at the onset of a myocardial infarction, despite aggressive anti-thrombotic treatment. The activation is more pronounced in diabetic subjects and tends to decrease within a few days. More targeted and effective anti-platelet therapy has the potential further to reduce cardiac and cerebral ischemic events following myocardial infarction and ongoing clinical trials are addressing this issue.