Antiplatelet Therapy in Acute Myocardial Infarction and Cardiogenic Shock: Insights From the National Cardiogenic Shock Initiative.

BACKGROUND: Patients presenting with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) are at high risk for impaired antiplatelet activity secondary to malabsorption, systemic hypoperfusion, hypothermia, need for mechanical ventilation, and high use of analgesics. The use of antiplatelet therapy in these high-risk patients is not well studied. METHODS: Using the National Cardiogenic Shock Initiative database, we analyzed patients who presented with AMI-CS at 60 hospitals from March 2018 to December 2020. All patients were treated using a standard shock protocol. Herein, the patterns of antiplatelet use are described. RESULTS: A total of 204 patients were included in the analysis, of which 174 (85.3%) presented with ST-segment elevation myocardial infarction (STEMI). The majority (84.3%) received antiplatelet therapy before percutaneous coronary intervention (PCI); of those who received antiplatelets, 77.9% received aspirin, 55.2% received an oral P2Y12 inhibitor, and 19.2% received intravenous (IV) antiplatelet therapy. Ticagrelor was the most common P2Y12 inhibitor administered (41.9%), followed by clopidogrel (12.2%) and prasugrel (1.2%). Only 18.6% of oral antiplatelet agents were crushed. Baseline characteristics of patients who received IV vs non-IV antiplatelet agents were similar. Thrombolysis in Myocardial Infarction (TIMI) 0 flow was present in 69.6% of patients before PCI and aspiration thrombectomy was performed in 24.5% of patients. The presence of STEMI, cardiac arrest, cardiopulmonary resuscitation, hypothermia, vasopressor use, elevated lactate levels, or number of vessels treated did not influence the use of IV antiplatelet agents. CONCLUSIONS: The use of crushed and IV antiplatelet agents in AMI-CS is low. Further studies are needed in this high-risk population to assess whether more potent antiplatelet inhibition will improve outcomes.

Anti-human leukocyte antigen antibodies are associated with restenosis after percutaneous coronary intervention for cardiac allograft vasculopathy.

BACKGROUND: Percutaneous coronary intervention (PCI) to palliate cardiac allograft vasculopathy (CAV) has been associated with high restenosis rates, possibly related to increased inflammation associated with this disease. Whether markers of immunologic rejection are associated with restenosis in this population is unknown. The goal of the study was to determine the predictors of restenosis after PCI for CAV. METHODS: Records were reviewed retrospectively from a single, high-volume cardiac transplant center. Clinical, angiographic, and immunologic data were collected on all patients postorthotopic heart transplantation (OHT) that had subsequent PCI. Restenosis was defined as greater than 50% stenosis at the previous intervention site. RESULTS: PCI was successfully performed on 62 de novo lesions in 40 patients an average of 6.8+/-3.9 years after OHT. Angiographic follow-up data was available for 79%, with an average follow-up of 1.54+/-1.22 years. The 1-year restenosis rate was 49% (64% for balloon percutaneous transluminal coronary angioplasty and 33% for coronary stenting [P=0.09 for difference]). The frequency of immunoglobulin (Ig)G antibody to major histocompatibility complex (MHC) class I antigen was highly associated with risk of restenosis (hazard ratio [HR] 11.33, P=0.01). Greater stenosis severity and smaller target vessel diameter were also predictors of restenosis as in the nontransplant population. CONCLUSIONS: The findings suggest that in patients postPCI for CAV, humoral allo-immunity may contribute to restenosis and that IgG antibodies to MHC class I antigen may help predict the risk of restenosis after PCI in this population.