Coronary spasm and vasomotor dysfunction as a cause of MINOCA

Increasing evidence has shown that coronary spasm and vasomotor dysfunction may be the underlying cause in more than half of myocardial infarctions with non-obstructive coronary arteries (MINOCA) as well as an important cause of chronic chest pain in the outpatient setting. We review the contemporary understanding of coronary spasm and related vasomotor dysfunction of the coronary arteries, the pathophysiology and prognosis, and current and emerging approaches to diagnosis and evidence-based treatment.

Assessment of Dofetilide or Sotalol Tolerability in the Elderly

Background: Dofetilide and sotalol are potassium channel antagonists that require inpatient QTc monitoring during initiation, due to increased risk of fatal arrhythmias. Elderly patients are especially subject to an increased risk of fatal arrhythmias due to polypharmacy, comorbidities, and physiologic cardiac changes with aging. This study will describe the tolerability and risk factors associated with the initiation of sotalol or dofetilide in patients ≥80 years of age. Methodology: This is a multicenter, retrospective, descriptive study of patients ≥80 years old who were initiated on either dofetilide or sotalol between May 8, 2018 and July 31, 2021 at institutions within the Mayo Clinic Health System. The percentage of patients who received nonpackage insert recommended doses was identified. Incidence of and reasons for dose reductions or discontinuations due to safety-related events or clinical concerns during the initial loading period were collected. Results: The final analysis included 104 patients. The majority of patients (75%) received nonstandard initial doses of dofetilide or sotalol based on baseline estimated creatinine clearance or QTc. Overall, 39% (N = 41) of patients experienced a dose reduction or discontinuation due to a safety-related event or concern. Patients who received nonstandard initial doses of dofetilide or sotalol had 4.7 times greater odds of experiencing a safety-related event requiring dose reduction or discontinuation. Conclusion: Following package insert dosing in elderly patients increases safety and tolerability relative to more aggressive dosing of dofetilide or sotalol.

Assessment of bleeding risk in low-weight patients receiving prophylactic subcutaneous unfractionated heparin

BACKGROUND

Underweight patients may be at an increased risk of bleeding while receiving venous thromboembolism (VTE) prophylaxis. Additional evidence is needed to identify patient-specific factors associated with bleeding. The objective of the study was to describe the incidence and identify risk factors associated with bleeding in low-weight (⩽ 60 kg) adult patients receiving subcutaneous unfractionated heparin (SQH) for VTE prophylaxis.

METHODS

This was a single-center, retrospective, nested case-control study of low-weight patients receiving SQH for VTE prophylaxis for ⩾ 48 hours. Cases, patients with clinically relevant bleeding while receiving SQH, and controls, patients without a bleeding event, were matched in a 1:3 ratio for age, sex, primary service (surgical or medical), and time at risk of bleeding on SQH to determine factors associated with bleeding.

RESULTS

A total of 3761 patients met the inclusion criteria, of which 38 cases of clinically relevant bleeding were identified. The bleeding incidence was 1% at hospital day 6 and 2.8% at hospital day 14. Most patients in this study (69%) received SQH 5000 units three times daily. ICU admission at SQH start was associated with bleeding, OR 2.97 (95% CI 1.21-7.29).

CONCLUSION

Bleeding in low-weight patients on prophylactic SQH was uncommon. Patients admitted to the ICU at time of SQH start may be at a higher risk of bleeding. Further studies are needed to detect additional risk factors associated with bleeding and investigate the effects of reduced dosing in this population.

A Single-Center Bleeding Comparison of Warfarin Plus Aspirin or Clopidogrel Following Coronary Artery Bypass Grafting and Surgical Valve Replacement

The optimal antithrombotic therapy following combined coronary artery bypass graft (CABG) and surgical valve replacement (SVR) surgery remains unclear. The aim of this single-center, retrospective cohort study was to assess the safety and effectiveness of a vitamin K antagonist (VKA) plus either aspirin or clopidogrel in patients following combined CABG and SVR. The primary endpoint was the occurrence of bleeding within six months. The secondary endpoint was the occurrence of CV death, stroke, acute coronary syndrome (ACS), or valve dysfunction. Outcomes were identified by pre-specified ICD codes. A total of 629 patients were included in the analysis, with 583 patients receiving aspirin and 46 patients receiving clopidogrel. Bleeding occurred in 1.7% of patients receiving aspirin and in 0% of patients receiving clopidogrel (p  =  0.99). CV death, stroke, ACS, or valve dysfunction occurred in 3.1% of patients receiving aspirin and 4.3% of patients receiving clopidogrel (p  =  0.65). In this study, there were no differences in the safety or effectiveness of a VKA plus either aspirin or clopidogrel following combined CABG and SVR.

Safety Comparison of Monotherapy Aspirin to Dual Antiplatelet Therapy Following Coronary Artery Bypass Surgery

Background

Dual antiplatelet therapy (DAPT) is recommended over single antiplatelet therapy (SAPT) in patients following coronary artery bypass grafting (CABG). The compilation of evidence has focused on the efficacy of DAPT to limit risk of graft occlusion, however the safety, especially in the on-pump CABG population, is less well described. The aim of this study was to assess the safety of DAPT versus SAPT after on-pump CABG.

Methods

This was a single-center, retrospective cohort analysis of adult patients following isolated on-pump CABG between January 2012 and December 2019 not on oral anticoagulation at discharge. The primary endpoint was occurrence of a composite bleeding event identified by pre-specified ICD codes. Secondary endpoints consisted of 30-day and 1-year mortalities along with individual bleeding components.

Results

Of the 2341 patients included 1250 patients were in the SAPT arm and 1091 patients in the DAPT arm. The study populations differed by age, prior MI, PAD, and CHF status/stage. Bleeding events occurred in a total of 70 patients (3.0%), with 36 patients (2.9%) in the SAPT arm and 34 patients (3.1%) in the DAPT arm (P = .74). 30-day (SAPT 0.7% vs DAPT 0.4%) and 1-year (SAPT 3.3% vs DAPT 2.3%) mortality were not significantly different between groups. The most frequent bleed event was in the gastrointestinal tract.

Conclusion

In this study, DAPT was not associated with an increase in composite bleeding compared to SAPT. This study could reduce the barrier to prescribing of DAPT given previous efficacy data.

Safety and Efficacy of Oral Anticoagulants for Atrial Fibrillation in Patients After Bariatric Surgery

Anticoagulation management is challenging in bariatric surgery patients, due to altered gastrointestinal anatomy and potentially reduced absorption. Few studies have evaluated clinical outcomes in this population. The objective of this study was to compare the efficacy and safety of oral anticoagulants in patients with and without a history of bariatric surgery. A retrospective, matched cohort study was conducted, utilizing data from the OptumLabs Data Warehouse. Patients ≥18 years old, with nonvalvular atrial fibrillation (NVAF), and treated with an oral anticoagulant between January 1, 2010 and December 31, 2018 were included. Outcomes were compared between bariatric and nonbariatric surgery patients. Secondary analysis compared warfarin to the direct oral anticoagulants (DOAC) in the bariatric cohort. The primary efficacy outcome was the rate of ischemic stroke and systemic embolism and the primary safety outcome was major bleeding. A total of 1,673 bariatric surgery and 155,619 nonbariatric surgery patients were identified. There was no significant difference in the rate of ischemic stroke or systemic embolism (0.83 vs 1.32 per 100 person years; Hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.31 to 1.22; p = 0.17) or major bleeding (5.30 vs 4.87 per 100 person years; HR 1.05, 95% CI 0.80 to 1.37; p = 0.73) between bariatric and nonbariatric surgery patients. In bariatric surgery patients alone, efficacy and safety were similar with warfarin compared with the DOACs. Results of this study suggest that bariatric surgery patients are not at an increased thrombotic or bleeding risk when using oral anticoagulants for NVAF. DOACs may be a reasonable alternative to warfarin.