Cutting Edge Treatments for Heart Failure

Heart failure is fluid build up in the lungs secondary to a heart problem. This includes leaky heart valves, reduced heart muscle pumping strength, or thickened heart muscle that doesn’t relax the way it should. While surgery is an option for select patients, the high cost, limited availability, and high risks involved mean that medical management of heart failure is typically recommended.

Standard therapies for heart failure vary depending on the underlying condition, and include medicines to improve the heart’s pumping function (pimobendan), slow heart rate (atenolol), reduce fluid retention (lasix, torsemide), and block hormones involved in long-term fluid build-up (spironolactone, enalapril, benazepril). Unfortunately, while patients have excellent quality of life with these treatments, they are not long-lasting – most pets have good quality of life for 6-12 months with treatment.

Researchers are hard at work investigating other medication options. The remainder of this article focuses on novel treatments that are currently being studied in pets, and are of great interest to the team at Apex as we strive for the most comprehensive and up-to-date management of your pet’s heart disease!

SGLT-2 Inhibitors

This is a class of medications that promotes glucose (sugar) excretion in the urine which improves fluid excretion to prevent build up in the lungs. In addition, the medication can reduce blood pressure and workload on the heart, reduce scarring of heart muscle, improve heart muscle pumping function, improve kidney function, and enhance red blood cell production for improved oxygenation. SGLT-2 inhibitors have clear benefit in reducing mortality and hospitalization in human patients. Studies are underway in veterinary patients.

Sacubitril/Valsartan

This is a combo of two drugs. The first is a neprilysin inhibitor – this reduces breakdown of BNP (thereby increasing active levels in the body). BNP is produced by the heart and has beneficial effects in heart failure (increasing urine output, lowering blood pressure, etc.). The second is an angiotensin receptor inhibitor. This improves blood pressure and blocks hormones involved in fluid retention. Small studies in dogs have shown improved heart size and blood pressure when taking this medication, but long-term effects are not yet known. Previously, this medication has been cost prohibitive, but the FDA recently (2025) approved a generic version making it much more accessible. Blood pressure and kidney values should be carefully monitored when taking this medication.

Rapamycin

This medication inhibits mTOR which is a growth signaling protein in the heart. It has been used in human transplant patients to minimize transplant failure, but long-term use carries side-effects including infections and delayed wound healing. A small study in cats with HCM suggested it might slow thickening of heart muscle, but did not change left atrial size (a much more important indicator of risk for symptoms). A much larger study is currently underway (the HALT trial), and we will have more information about whether or not this will be helpful for cats with HCM in the near future.

Visit felineheartstudy.com to learn about an ongoing study and see if your cat is eligible to participate! If your pet meets initial screening criteria, all visit costs are covered.

References:https://link.springer.com/article/10.1007/s00125-018-4670-7 https://onlinelibrary.wiley.com/doi/full/10.1111/jvim.15240 https://www.hcmincats.com/halt