Prasugrel vs. clopidogrel in acute coronary syndrome patients treated with prasugrel

Comparison of 6-Month Costs Between Oral Antiplatelet Agents Following Acute Coronary Syndrome

BACKGROUND

In patients with acute coronary syndrome (ACS) treated with percutaneous coronary intervention (PCI), newer antiplatelet agents prasugrel and ticagrelor have lower rates of cardiovascular events when compared with clopidogrel. However, it is unclear whether there are differences in economic outcomes when comparing these agents in ACS-PCI patients.

OBJECTIVE

To assess aggregated costs and medical resource utilization among ACS-PCI patients prescribed prasugrel, ticagrelor, or generic clopidogrel, using a large commercial insurance claims database.

METHODS

Costs attributable to any medical and pharmacy service and resource utilization including number of admissions, length of hospital stay, emergency room visits, and office visits over the 180-day postdischarge period were compared. All-cause and cardiovascular health care costs and resource utilization were separately analyzed for patients enrolled in the data over the continuous follow-up (CFU) period, and for patients continuously taking their initial treatment for 6 months (CTX). Potential confounders collected over a 6-month baseline assessment period were controlled for, using a generalized linear model.

RESULTS

Over the 180-day follow-up, prasugrel and ticagrelor patients underwent fewer admissions (rate ratio [RR] = 0.87, 95% CI = 0.80-0.95) from CFU and RR = 0.81, 95% CI = 0.71-0.89 from CTX) compared with clopidogrel patients. The newer agent cohort incurred more overall health care costs than the generic clopidogrel group, with added costs of $957 (95% CI = $236-$1,725) in the CFU group and $1,122 (95% CI = $455-$1,865) in the CTX group, which were smaller than the increase in all-cause outpatient pharmacy costs associated with the newer agents versus clopidogrel (CFU: $1,175, 95% CI = $1,079-$1,278 and CTX: $1,360, 95% CI = $1,256-$1,487). Overall, there was no statistically significant difference in the economic outcomes associated with prasugrel and ticagrelor. There were, however, significant correlations between all-cause and cardiovascular-related outcomes.

CONCLUSIONS

The higher price of prasugrel and ticagrelor was partially offset by a decrease in hospital admission compared with generic clopidogrel over a 6-month postdischarge period. Aggregated medical costs and resource utilization were not significantly different between prasugrel and ticagrelor patients.

DISCLOSURES

No funding was received for this study. DiDomenico has received an honorarium from Amgen for preparation of a heart failure drug monograph for Pharmacy Practice News and serves as an advisory board member for a heart failure program at Otsuka America Pharmaceuticals and for Novartis Pharmaceuticals. Touchette has received unrestricted grant funding from Cardinal Health, Sunovion Pharmaceuticals, and Takeda and has served as a consultant to and director of the American College of Clinical Pharmacy Practice-Based Research Network on a study funded by Pfizer. Walton has served as a paid consultant for Bristol-Myers Squibb, Baxter, Merck, Genentech, Primus, Takeda, and Abbott. The other authors have nothing to disclose.

Role of P2Y12 Receptor in Thrombosis

P2Y₁₂ receptor is a 342 amino acid Gi-coupled receptor predominantly expressed on platelets. P2Y₁₂ receptor is physiologically activated by ADP and inhibits adenyl cyclase (AC) to decrease cyclic AMP (cAMP) level, resulting in platelet aggregation. It also activates PI3 kinase (PI3K) pathway leading to fibrinogen receptor activation, and may protect platelets from apoptosis. Abnormalities of P2Y₁₂ receptor include congenital deficiencies or high activity in diseases like diabetes mellitus (DM) and chronic kidney disease (CKD), exposing such patients to a prothrombotic condition. A series of clinical antiplatelet drugs, such as clopidogrel and ticagrelor, are designed as indirect or direct antagonists of P2Y₁₂ receptor to reduce incidence of thrombosis mainly for patients of acute coronary syndrome (ACS) who are at high risk of thrombotic events. Studies on novel dual-/multi-target antiplatelet agents consider P2Y₁₂ receptor as a promising part in combined targets. However, the clinical practical phenomena, such as "clopidogrel resistance" due to gene variations of cytochrome P450 or P2Y₁₂ receptor constitutive activation, call for better antiplatelet agents. Researches also showed inverse agonist of P2Y₁₂ receptor could play a better role over neutral antagonists. Personalized antiplatelet therapy is the most ideal destination for antiplatelet therapy in ACS patients with or without other underlying diseases like DM or CKD, however, there is still a long way to go.

Economic outcomes with prasugrel versus clopidogrel in acute coronary syndrome patients: observations from prasugrel users and matched clopidogrel users

OBJECTIVE

To compare healthcare costs between clopidogrel and prasugrel over 30-day and 365-day periods after discharge from the hospital or emergency room (ER) in patients treated with prasugrel who were hospitalized or had an ER visit for an acute coronary syndrome (ACS) event.

METHODS

This retrospective observational study was based on claims from January 2009-July 2012 in the Truven Health Analytics MarketScan database. Clopidogrel patients were propensity-score matched 1:1 to prasugrel-treated patients. Lin's frequentist cost history method for censored data and Bayesian zero-inflated gamma regression models were used to analyze healthcare costs.

RESULTS

The clopidogrel/prasugrel matched-cohort included 10,963 well-matched pairs of patients. Lin's frequentist analysis showed that outpatient visit costs were significantly lower for clopidogrel than prasugrel after 30 days of follow-up. At 30 days, Bayesian data analysis showed strong evidence that clopidogrel was superior to prasugrel for all-cause and ACS-related hospitalization costs and showed very strong evidence that clopidogrel was superior to prasugrel for all-cause and ACS-related outpatient visit costs. At 365 days, Bayesian data analysis showed strong evidence that clopidogrel was superior to prasugrel for all-cause outpatient visit costs and very strong evidence that clopidogrel was superior to prasugrel for ACS-related outpatient visit costs. Point estimates of the all-cause and ACS-related ER visit costs at 30 days and 365 days were similar, but statistical results were inconclusive because of the large variability in this outcome variable.

CONCLUSION

Based on retrospective observational data in a real-world setting, all-cause and ACS-related hospitalization and outpatient visit costs were lower for clopidogrel than prasugrel over 30 days after discharge from a hospitalization or ER visit associated with ACS in patients treated with prasugrel. At 365 days the difference in all-cause and ACS-related outpatient costs remained, but there was little evidence of a difference in either all-cause or ACS-related hospitalization costs.