Ticagrelor vs clopidogrel followed by ticagrelor re-loading in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: A randomized, pharmacodynamic comparison

Dual Loading Antiplatelet Therapy in Patients With Acute Coronary Syndrome and High Bleeding Risk Undergoing Percutaneous Coronary Intervention: Findings From the Improving Care for Cardiovascular Disease in China Project

Objective

Loading dose of dual antiplatelet therapy (LD) is supported by the guidelines for patients with acute coronary syndrome (ACS). However, limited data is provided in the series of high bleeding risk (HBR) patients with ACS and percutaneous coronary intervention (PCI).

Methods

Using data from the Improving Care for Cardiovascular Disease in China—Acute Coronary Syndrome registry, conducted between 2014 and 2019, we stratified all ACS patients with HBR and PCI according to LD used within 24 h of first medical contact or not. Inverse probability of treatment weighting (IPTW) and Cox proportional hazards model with hospital as random effect were used to analyze differences in in-hospital clinical outcomes: the primary efficacy endpoint was mortality, and the primary safety endpoint was bleeding.

Results

Of 21,654 evaluable patients 14,322 (66.2%) were treated with LD, and were on average older, less likely to have comorbidities and higher hemoglobin, more often treated GPI and anticoagulant during hospitalization than those without LD. After IPTW adjustment for baseline differences, LD was associated with significantly increased risk of in-hospital mortality [1.89 vs. 1.02%; hazard ratio (HR): 1.71 (95% confidence interval 1.12, 2.42); p < 0.001] and in-hospital bleeding [3.89 vs. 3.3%; HR: 1.25 (1.03, 1.53); p = 0.03].

Conclusions

In ACS patients with HBR, LD was associated with an increased risk of in-hospital mortality and bleeding complications after PCI. Dedicated randomized trials with contemporary ACS management are needed to confirm these findings.

Does the level of myocardial injury differ in primary angioplasty patients loaded first with clopidogrel and the ones with ticagrelor?

Objective:

In daily clinical practice, we encounter ST segment elevation myocardial infarction (STEMI) patients loaded with clopidogrel upon admission to primary angioplasty. These patients are loaded with ticagrelor, if there is no contraindication. This study aimed to compare the level of injury between STEMI patients who were first loaded with clopidogrel and the ones first loaded with ticagrelor. Although patients were switched from clopidogrel to ticagrelor at the first hour of angioplasty, antiplatelet action may still be lower than the others.

Methods:

This study included STEMI patients with angina onset of ≤3 h and who had primary angioplasty to proximal segment of one coronary artery. All patients had total thrombotic occlusion at the proximal segment. Δtroponin level (6^th-hour troponin–admission troponin) was calculated to compare the level of myocardial injury.

Results:

A total of 105 patients were included; 52 were loaded with ticagrelor and 53 with clopidogrel first and switched to ticagrelor. Baseline characteristics were similar in the two groups, except from type B2 lesions being more common in the ticagrelor-loaded group. Δtroponin levels were significantly higher in the clopidogrel-loaded group compared with the ticagrelor-loaded group (p=0.013). Major bleeding and in-hospital MACE rates were similar in both groups.

Conclusion:

In STEMI patients, the degree of troponin rise was more prominent in clopidogrel-loaded patients, despite the switch to ticagrelor in the first hour of intervention. Clopidogrel is slow and modest, and variable platelet inhibition may continue to be a negative factor for protection from myocardial injury, even after switching to ticagrelor.

Combination antiplatelet treatment in coronary artery disease patients: A necessary evil or an overzealous practice?

In seeking to improve care in coronary artery disease patients, further platelet inhibition has been occasionally applied beyond that provided by aspirin and a P2Y₁₂ receptor antagonist. This review aims to offer insights about the rationale, the efficacy and safety of combination antiplatelet therapy, involving three or more agents. Overall, the use of glycoprotein (GP) IIb/IIIa inhibitors did not significantly modify the treatment effect of different antiplatelet strategies, including double vs standard clopidogrel, prasugrel vs clopidogrel, ticagrelor vs clopidogrel, cangrelor vs clopidogrel, and vorapaxar vs placebo. With the caveat that the use of GP IIb/IIIa inhibitor was not randomized, adding such an agent to aspirin and a P2Y₁₂ receptor antagonist appears to carry a significantly increased bleeding potential. Moreover, adding vorapaxar to aspirin- and clopidogrel-treated patients is associated with more bleeding events, while the bleeding potential is further exacerbated in cases of quadruplicate antiplatelet treatment including aspirin, clopidogrel, vorapaxar, and a GP IIb/IIIa inhibitor. In ST-segment elevation, myocardial infarction patients' administration of an intravenous antiplatelet agent (GP IIb/IIIa inhibitor or cangrelor), in addition to aspirin and a P2Y₁₂ receptor antagonist, efficiently bridges the pharmacodynamic gap of oral agents. Cilostazol on top of aspirin and clopidogrel appears to be safe, although of questionable clinical benefit. In conclusion, combination antiplatelet therapy should be reserved only for selected cases and following thoughtful consideration of the associated risk/benefit ratio.