ORLANDO — In a large study of older patients with type 2 diabetes and heart failure (HF), researchers found those taking aspirin for primary prevention had a lower mortality, specifically all-cause mortality with or without HF hospitalization over 5-year follow-up, but were paradoxically more likely to have a nonfatal myocardial infarction (MI) or stroke.
Surprisingly, bleeding risks were similar in both groups.
The findings are from an observational study of patients seen in primary care in the United Kingdom, with lead author Charbel Abi Khalil, MD, Weill Cornell Medicine-Qatar, Doha.
"There are no clear guidelines on aspirin use in this category of patients" with type 2 diabetes and HF and no prior stroke or MI, and this explains why in this study, half were receiving aspirin and half were not, Abi Khalil told theheart.org | Medscape Cardiology in an email.
"We were surprised to see a paradoxical increase in nonfatal heart attacks and nonfatal stroke, parallel to the decrease in mortality," he said in a statement, speculating that patients in this age group were more likely to have a cardiac event.
However, he cautioned, "this is a retrospective study," so it is too early to draw treatment recommendations from these findings.
In the meantime, if he were sitting across from a patient who has diabetes and HF, he said he would take into account several factors, including his or her cardiovascular risk factors and age, and determine the patient's risk profile. If the risks of having a blood clot or heart attack are greater than the risk of having a hemorrhage, he would put the patient on aspirin.
The findings will be presented March 11 at the American College of Cardiology at the American College of Cardiology (ACC) 2018 Scientific Sessions.
Paul A Gurbel, MD, Inova Heart and Vascular Institute, Falls Church, Virginia, who was not involved in the study, told theheart.org | Medscape Cardiology that nearly half of patients with type 2 diabetes will develop HF.
He too noted that there are no specific guideline recommendations for primary prevention with aspirin in such patients, and the current retrospective study has inherent limitations, as acknowledged by the authors.
Like Abi Khalil, he said that for now, physicians should estimate an individual patient's risk of future cardiovascular events by using an established risk calculator, and then balance this with the potential risk for bleeding, to determine whether aspirin therapy is warranted.
The primary-prevention data in the current study, he noted, "are not in line with the stronger evidence for secondary prevention."
According to Gurbel, "the absence of increased bleeding in the aspirin treated patients is surprising." Moreover, "the increase in nonfatal MI/stroke in the aspirin group is difficult to explain, and the mechanism for less death and HF hospitalization in the [aspirin] group is similarly challenging to explain," he added, all of which points to the need for further research.
Primary Care Patients With Diabetes and HF
To investigate the impact of aspirin for primary prevention in patients with type 2 diabetes and heart failure, Abi Khalil and colleagues identified 12,534 patients in The Health Improvement Network (THIN) database of patients seen in primary care in the United Kingdom.
Patients were 55 years of age or older with no previous MI, stroke, peripheral artery disease, or atrial fibrillation.
Just over half (6567 patients) were not taking aspirin, and of the others who were taking aspirin, most were taking low-dose (75 mg/day) aspirin. Only 137 patients were taking higher dose aspirin (≥100 mg/day).
During a mean follow-up of 5.2 years and up to 16.7 years, the primary outcome — a composite of all-cause mortality with or without hospitalization for HF — was 10% less likely in the patients who were taking aspirin (hazard ratio, 0.89; 95% CI, 0.84 - 0.94), after multivariable adjustment.
However, patients who were taking aspirin had a 50% increase risk for nonfatal MI or stroke, but without any significant difference in risk for major bleeding.
The study was funded by the biomedical research program at Weill Cornell Medicine-Qatar, a program supported by Qatar Foundation. Abi Khalil has no relevant financial disclosures. Gurbel discloses receiving honoraria or consulting fees from Janssen, Bayer, World Medical, Aralez, Haemonetics, Rockpointe, and Ionis and grants from Amgen, Janssen, Bayer, Merck, Medicure, Werfen, idorsia, and Haemonetics.
American College of Cardiology (ACC) 2018 Scientific Session. Abstract 432. To be presented March 11, 2018.
Medscape Medical News © 2018
Cite this: Aspirin Linked to Lower Mortality in Diabetes With Heart Failure - Medscape - Mar 09, 2018.