Cardiologists account for small proportion of all use of SGLT2is and GLP-1RAs
National Trends in Use of Sodium‐Glucose Cotransporter‐2 Inhibitors and Glucagon‐like Peptide‐1 Receptor Agonists by Cardiologists and Other Specialties, 2015 to 2020
Introduction and methods
Despite the cardiovascular benefits of SGLT2is and GLP‐1RAs, they are not prescribed to most T2DM patients with established CVD or additional cardiovascular risk factors. Several prominent clinical guidelines and awareness campaigns have specifically called upon cardiologists to take the lead in deploying these drugs [1-4].
Aim of the study
In this descriptive analysis, the pattern of SGLT2i and GLP‐1RA prescription by cardiologists and noncardiologists in the USA from 2015 through 2020 was examined.
The authors analyzed data from IQVIA’s National Prescription Audit (NPA) from January 2015 through December 2020. This comprehensive audit captures ~90% of all retail prescriptions dispensed in the USA. NPA‐generated projections of total dispensed prescription volume were used to estimate monthly SGLT2is and GLP-1RAs dispensed, stratified by prescriber specialty and drug molecule. To calculate the average number of annual dispensed prescriptions per physician, the NPA-generated projections of total dispensed prescription volume were combined with aggregate physician census data for each specialty from the American Medical Association’s Physician Masterfile.
- From January 2015 through December 2020, 63.2 million SGLT2i and 63.4 million GLP‐1RA medications were dispensed in the USA.
- The average annual prescription rate was +15.6% for SGLT2is and +25.2% for GLP-1RAs.
- In 2020, SGLT2is and GLP-1RAs were mostly prescribed by primary care physicians/internists (57% and 52%, respectively), while cardiologists accounted for <2% of all SGLT2i and GLP‐1RA prescriptions.
- Monthly prescriptions dispensed by cardiologists increased 12-fold for SGLT2is (from 2228 to 25,815) and 4-fold for GLP-1RAs (from 1927 to 6981).
- The average number of dispensed prescriptions per physician in 2020 was highest for endocrinologists (272 SGLT2is and 405 GLP-1RAs), followed by primary care physicians/internists (18 and 20, respectively) and cardiologists (6 and 2, respectively).
- During the study period, cardiologists, but not noncardiologists, increasingly prescribed SGLT2is over GLP-1RAs.
- This trend started in late 2015/early 2016 and mainly consisted of accelerated use of the SGLT2i empagliflozin, following publication of the results of the landmark EMPA‐REG OUTCOME trial and the US Food and Drug Administration (FDA) label expansion for empagliflozin regarding CVD risk reduction in T2DM [5,6].
- In 2020, empagliflozin was the most widely prescribed SGLT2i among cardiologists (67% of SGLT2is dispensed) and noncardiologists (58%).
- From September 2019 through December 2020, empagliflozin’s share of SGLT2i prescriptions among cardiologists declined 18%, while dapagliflozin’s share increased 23%, following a decrease since 2015. This trend coincided with the publication of the DAPA‐HF trial and the FDA label expansion for dapagliflozin to include treatment of HFrEF patients with and without T2DM [7,8].
- The relative use of canagliflozin declined from 65% of all SGLT2i prescriptions in January 2015 to 3% in December 2020.
- There were no shifts in GLP-1-RA prescriptions following publication of the results of cardiovascular outcomes trials or associated FDA drug label changes.
- During the study period, the share of daily injected GLP‐1RAs—such as liraglutide and short‐acting exenatide— decreased from 76% to 19%, which was accompanied by a reciprocal increased share of weekly-injection GLP‐1RAs—such as dulaglutide, subcutaneous semaglutide, and long‐acting exenatide .
- The most prescribed GLP‐1RA in 2020 was dulaglutide (39% of cardiology GLP‐1RAs and 45% of noncardiology GLP‐1RAs), followed by semaglutide (37% and 28%, respectively).
Analysis of a near–census‐level audit of US retail prescriptions showed a 12-fold increase in SGLT2i prescriptions and a 4-fold increase in GLP‐1RA prescriptions by cardiologists from 2015 through 2020. However, cardiologists accounted for <2% of all dispensed prescriptions for these drugs, which could contribute to the undertreatment of T2DM patients with a high CVD risk. According to the authors, “[their] results demonstrating a limited role of cardiologists in disseminating SGLT2i and GLP‐1RA therapies present an opportunity to optimize access to these cardiometabolic therapies.”