Temporal trends and practice variations in clopidogrel loading doses in patients with non-ST-segment elevation myocardial infarction, from the National Cardiovascular Data Registry

Clinical characteristics and outcomes of young adults with first myocardial infarction: Results from Gulf COAST

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CVD risk factors are common in young Gulf-Arabs presenting with first AMI.

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Older AMI patients receive less potentially lifesaving therapies than young adults.

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In-hospital adverse CVD events and mortality were low in young adults with AMI.

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Mortality up to 12-months post-AMI was lower in young adults than in older adults.

Introduction

Limited data exists on the risk factor profile and outcomes of young patients suffering their first acute myocardial infarction (AMI).

Methods

We examined 1562 Gulf-Arabs without prior cardiovascular disease presenting with first AMI enrolled in the Gulf COAST prospective cohort. Clinical characteristics were compared in patients ≤50 years of age (young) vs. >50 years (older). Associations between age group and in-hospital adverse events (re-infarction, heart failure, cardiogenic shock, cardiac arrest, stroke, and in-hospital death) or post-discharge mortality were estimated using logistic regression.

Results

Young patients represented 26.1% (n = 407) of first AMI cases and were more likely to be men (82.8% vs. 66.5%), current smokers (49.9% vs 19.0%), obese (38.3% vs 28.0%), and have family history of premature coronary artery disease (21.4% vs 10.4%) compared with older patients (all P < 0.001). Young patients were more likely to receive β-blockers (83.0% vs 74.4%; P < 0.001), clopidogrel (82.3% vs 76.0%; P = 0.009) and primary reperfusion therapy (85.6% vs. 75.6%; P = 0.003). Young adults had lower in-hospital death (adjusted odds ratio [aOR] = 0.37; 95%CI = 0.16–0.86) or any in-hospital adverse cardiovascular events (aOR = 0.53; 95%CI = 0.34–0.83). Young adults had lower likelihood of cumulative death at 12-month post-discharge (aOR = 0.34; 95%CI = 0.19–0.59) after adjusting for potential confounders.

Conclusion

Young patients with first AMI were more likely to be obese, smokers and have family history of premature coronary artery disease compared to older adults. Young patients were more likely to receive guideline-proven therapies and have better in-hospital and post-discharge mortality. These data highlight important age-related care gaps in patients suffering AMI for the first time.

Variation in Practice Regarding Pretreatment With Dual Antiplatelet Therapy for Patients With Non-ST Elevation Myocardial Infarction

BACKGROUND

Despite guideline recommendations, a significant number of patients with non-ST elevation myocardial infarction (NSTEMI) do not receive dual antiplatelet therapy (DAPT) before angiography "pretreatment." While there may be valid clinical reasons to not pretreat, such as concern for bleeding or multivessel disease warranting coronary artery bypass graft surgery, the degree of variability and factors associated with DAPT pretreatment are unknown.

METHODS AND RESULTS

From the multicenter TRIUMPH registry, 1632 NSTEMI patients were not taking DAPT on admission and were included in the study cohort. Among the study patients, only 22% patients received DAPT pretreatment. A multivariable logistic regression model showed that race other than white or black (odds ratio [OR] 0.41, 95% CI 0.21-0.83), hemoglobin level (OR 1.18, 95% CI 1.08-1.29), patients' bleeding risk (assessed with NCDR CathPCI Bleeding Risk Score) (OR 0.85, 95% CI 0.74-0.99), and severe left ventricular dysfunction (OR 0.3, 95% CI 0.13-0.65) were the main predictors of pretreatment with DAPT, whereas likelihood of needing coronary artery bypass graft surgery (GRACE prediction model) was not (OR 1.09, 95% CI 0.88-1.35). Median ORs were calculated to assess variability of receiving DAPT pretreatment across sites after adjustment for patient characteristics. Receiving DAPT pretreatment varied substantially across sites (range 0-100%, mean OR 3.94, P<0.0001).

CONCLUSIONS

While deviating from guideline-recommended DAPT pretreatment in patients with NSTEMI was associated with patient factors (eg, bleeding risk), marked variation was present across sites after accounting for patient-level characteristics. This suggests that site-level interventions are needed to improve concordance with current guidelines.

Predicting Likelihood for Coronary Artery Bypass Grafting After Non-ST-Elevation Myocardial Infarction: Finding the Best Prediction Model

BACKGROUND

Up to half of patients with non-ST-elevation myocardial infarction (NSTEMI) do not receive dual antiplatelet therapy before angiography "pretreatment" because of the risk of increased bleeding if coronary artery bypass grafting (CABG) operation is needed. Several models have been published that predict the likelihood of CABG after NSTEMI, but they have not been independently validated. The purpose of this study was to validate these models and improve the best one.

METHODS

We studied patients with NSTEMI who were enrolled in the 24-center Translational Research Investigating Underlying Disparities in Acute Myocardial Infarction Patients' Health Status (TRIUMPH) registry between 2005 and 2008. Previous CABG prediction models were assessed using c-statistics and calibration assessments to determine the best model. Variables from TRIUMPH likely to be associated with CABG were tested to see whether they could improve the best model's performance.

RESULTS

Among 2,473 patients with NSTEMI, 11.8% underwent in-hospital CABG. C-statistics for the Modified Thrombolysis in Myocardial Infarction, Treat Angina With Aggrastat and Determine the Cost of Therapy With an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction 18, Poppe, and Global Risk of Acute Coronary Events (GRACE) models were 0.54, 0.61, 0.61, and 0.62, respectively. The GRACE model showed the best discrimination and calibration. From the TRIUMPH registry, preselected variables were added to the GRACE model but did not significantly improve model discrimination. A GRACE model risk score of less than 9 had high sensitivity (96%), thus making it useful for predicting patients with NSTEMI who were at low risk for requiring CABG, which included approximately 21% of patients with NSTEMI.

CONCLUSIONS

This study could not improve on the GRACE model, which had the best predictive value for identifying a need for CABG after NSTEMI with a broader range of predicted risk levels and high sensitivity, especially in patients with scores lower than 9.

Why we need intravenous antiplatelet agents

Oral ADP-receptor antagonists combined with aspirin are the standard for dual antiplatelet therapy (DAPT) during percutaneous coronary intervention (PCI). However, the oral route of administration of ADP-receptor antagonists leaves them vulnerable to unpredictable and often inadequate platelet inhibition at the time of PCI, while their prolonged effects often lead to the decision not to load them prior to PCI. Intravenous antiplatelet agents, including glycoprotein IIb/IIIa inhibitors (GPI) and cangrelor, a reversible P2Y12 inhibitor, address these shortcomings. In June 2015, the US FDA approved cangrelor for the prevention of thrombotic events associated with coronary stenting. This review examines the current state of peri-PCI DAPT and demonstrates that the selective use of GPIs and intravenous ADP-antagonist agents reduces the risk of periprocedural thrombosis.