The benefits from sodium-glucose cotransporter 2 inhibitor drugs proven during the past year for cutting heart failure hospitalization rates substantially in patients with heart failure with reduced ejection fraction and slowing progression of chronic kidney disease, all regardless of diabetes status, have thrust this drug class into the top tier of agents for potentially treating millions of patients with cardiac or renal disease.
The sodium-glucose cotransporter 2 (SGLT2) inhibitors, first licensed for U.S. marketing in 2013 purely for glycemic control, have, during the 5 years since the first cardiovascular outcome trial results for the class came out, shown benefits in a range of patients reminiscent of what’s been established for ACE inhibitors and angiotensin receptor blockers (ARBs).
The wide-reaching benefits of SGLT2 inhibitors have recently become even more relevant by showing clinically meaningful effects in patients without type 2 diabetes (T2D). And in an uncanny coincidence, the SGLT2 inhibitors appear to act in complementary harmony with the ACE inhibitors and ARBs for preserving heart and renal function. These properties have made the SGLT2 inhibitors especially attractive as a new weapon for controlling the ascendant disorder of cardiorenal syndrome.
“SGLT2 inhibitors have a relatively greater impact on cardiovascular outcomes, compared with ACE inhibitors and ARBs, but the effects [of the two classes] are synergistic and ideally patients receive both,” said Peter McCullough, MD, a specialist in treating cardiorenal syndrome and other cardiovascular and renal disorders at Baylor, Scott, and White Heart and Vascular Hospital in Dallas. The SGLT2 inhibitors are among the drugs best suited to both treating and preventing cardiorenal syndrome by targeting both ends of the disorder, said Dr. McCullough, who chaired an American Heart Association panel that last year issued a scientific statement on cardiorenal syndrome (Circulation. 2019 Apr 16;139[16]:e840-78).
Although data on the SGLT2 inhibitors “are evolving,” the drug class is “going in the direction” of being “reasonably compared” with the ACE inhibitors and ARBs, said Javed Butler, MD, professor and chair of medicine at the University of Mississippi Medical Center, Jackson. “There are certainly complementary benefits that we see for both cardiovascular and renal outcomes.”
Dr. David Cherney
“We’ll think more and more about the SGLT2 inhibitors like renin-angiotensin system [RAS] inhibitors,” said David Z. Cherney, MD, referring to the drug class that includes ACE inhibitors and ARBs. “We should start to approach SGLT2 inhibitors like RAS inhibitors, with pleiotropic effects that go beyond glucose,” said Dr. Cherney, a nephrologist and professor of medicine at the University of Toronto, during the virtual annual scientific sessions of the American Diabetes Association in June 2020.
Working together in the nephron
One of the clearest complementary interactions between the SGLT2 inhibitors and the RAS inhibitors is their ability to reduce intraglomerular pressure, a key mechanism that slows nephron loss and progression of chronic kidney disease. SGLT2 inhibitors reduce sodium absorption in the proximal tubule that causes, through tubuloglomerular feedback, afferent arteriole constriction that lowers intraglomerular pressure, while the RAS inhibitors inhibit efferent arteriole constriction mediated by angiotensin II, also cutting intraglomerular pressure. Together, “they almost work in tandem,” explained Janani Rangaswami, MD, a nephrologist at Einstein Medical Center in Philadelphia, vice chair of the Kidney Council of the AHA, and first author of the 2019 cardiorenal syndrome AHA statement.