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DAPA-HF: Dapagliflozin benefits regardless of age, HF severity

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Dapagliflozin nears foundational status for HFrEF treatment

In DAPA-HF, treatment with dapagliflozin met the three critical goals of heart failure management. When used on top of current guideline-directed medical therapy, the treatment reduced mortality, cut hospitalizations, and improved heart failure–related health status – all to a similar extent regardless of patients’ age or symptom severity at entry. These new, post hoc findings provide important, additional data supporting inhibition of sodium-glucose cotransporter (SGLT) 2 with dapagliflozin as the newest foundational pillar of treatment for heart failure with reduced ejection fraction (HFrEF).

Dr. Carolyn S.P. Lam, professor of medicine at Duke-National University of Singapore Mitchel L. Zoler/MDedge News

Dr. Carolyn S.P. Lam

Analysis of the DAPA-HF results by age showed a consistent benefit from dapagliflozin treatment in older patients with HFrEF, compared with younger patients. This finding is important because patients more than 75 years old often have comorbidities, frailty, and polypharmacy use, any of which could potentially affect the risk/benefit relationship of the drugs they take. The absolute risk reduction is greater in older patients because of their higher baseline risk for cardiovascular events, while the relative risk reductions among the age strata were similar. Older patients also had more adverse events during the study, but the rate of these events was similar among patients on dapagliflozin treatment and those who received placebo, so in general dapagliflozin was well tolerated. Older patients were less likely to receive current guideline-directed medical therapy, which may have amplified the impact of dapagliflozin and also highlights the treatment inertia that can affect these patients.

The results of the analysis by baseline symptoms severity as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ) showed similar treatment effects from dapagliflozin regardless of a patient’s baseline KCCQ score, suggesting that the prior report of a blunted effect of dapagliflozin in patients classified at baseline as being in New York Heart Association functional class III or IV compared with class I and II patients was likely a chance finding.

Both the analyses by age and by KCCQ scores were limited by their post hoc status using data collected in a single study. No evidence addresses whether these are class effects for all drugs in the SGLT2-inhibitor class, whether these findings from DAPA-HF are generalizable to real world practice, or whether treatment with dapagliflozin would have similar effects on outcomes if it had been used more often in combination with sacubitril/valsartan. In DAPA-HF, 11% of patients also received sacubitril/valsartan even though existing management guidelines recommend sacubitril/valsartan as the preferred agent for inhibiting the renin-angiotensin system.

It’s also unclear whether patient-reported outcomes such as those measured by the KCCQ will help in sequencing the introduction of drugs for HFrEF patients, or drug selection by patients, providers, payers, and in guidelines.

Carolyn S.P. Lam, MD, is professor of medicine at Duke-National University of Singapore. She has been a consultant to and has received research funding from AstraZeneca and several other companies. She made these comments as designated discussant for the two reports.


 

REPORTING FROM THE AHA SCIENTIFIC SESSIONS

Dr. Mikhail N. Kosiborod, professor of medicine at the University of Missouri--Kansas City Mitchel L. Zoler/MDedge News

Dr. Mikhail N. Kosiborod

After the first 8 months of treatment in the DAPA-HF trial, 58% of the 2,373 patients who received dapagliflozin had a clinically meaningful improvement in their total KCCQ symptom score of at least 5 points, compared with a 51% rate in the 2,371 patients in the control arm, a statistically significant difference. This meant that the number needed to treat with dapagliflozin was 14 patients to produce one additional patient with at least a 5-point KCCQ improvement compared with controls, a “very small” number needed to treat, Dr. Kosiborod said in an interview.

Addition of the KCCQ to the panel of assessments that patients underwent during DAPA-HF reflected an evolved approach to measuring efficacy outcomes in clinical trials by including patient-reported outcomes. Earlier in 2019, the Food and Drug Administration released draft guidance for heart failure drug development that explicitly called for efficacy endpoints in pivotal studies that measure how patients feel and function, and stating that these endpoints can be the basis for new drug approvals.

“To many patients, how they feel matters as much if not more than how long they live,” Dr. Kosiborod noted. The goals of heart failure treatments are not only to extend survival and reduced hospitalizations, but also to improve symptoms, function, and quality of life, he said.

“There is a lot of interest now in having outcomes in heart failure trials that are more meaningful to patients, like feeling better and being able to do more,” noted Dr. Walsh.

The DAPA-HF results also showed that patients had similar rates of reduction in death, heart failure hospitalization, or urgent clinical visits, regardless of how severely they were affected by their heart failure when they began dapagliflozin treatment. The researchers ran an analysis that divided the entire trial population into tertiles based on their KCCQ score on entering the study. Patients in the most severely-affected tertile had a 30% cut in their rate of death or acute heart failure exacerbation on dapagliflozin compared with placebo, while patients in the tertile with the mildest symptoms at baseline had a 38% reduction in their primary outcome incidence compared with controls who received placebo. Concurrently with Dr. Kosiborod’s report, the results appeared in an article online (Circulation. 2019 Nov 17. doi: 10.1161/CIRCULATIONAHA.119.044138).

Outcomes by age

Not surprisingly in DAPA-HF, the older patients were, the sicker, Dr. McMurray observed. Of the study’s 1,149 patients (24% of the study cohort) who were at least 75 years old, 62% had chronic kidney disease, compared with a 14% prevalence among the 636 patients younger than age 55. The 75-and-older group showed a steeper, 32% decline in incidence of the primary endpoint – a composite of cardiovascular (CV) death, HF hospitalization, or urgent HF visit requiring intravenous therapy – than in the other studied age groups: a 24% decline in those 65-74 years old, a 29% cut in those 55-64 years old, and a 13% drop in patients younger than 55 years old.

In addition, patients aged 75 years or greater were just as likely as the overall group to show at least a 5-point improvement in their KCCQ Total Symptom Score on dapagliflozin, as well as about the same reduced rate of deterioration compared with placebo as tracked with the KCCQ.

Patients “got as much benefit in terms of symptoms as well as morbidity and mortality,” Dr. McMurray concluded. Concurrently with the meeting report the results appeared in an article online (Circulation. 2019 Nov 17. doi: 10.1161/CIRCULATIONAHA.119.044133).

“These data are of critical importance, as improving patient-reported outcomes in heart failure, especially in highly symptomatic patients, is an important goal in drug development,” G. Michael Felker, MD, wrote in an editorial accompanying the two published analyses (Circulation. 2019 Nov 17. doi: 10.1161/CIRCULATIONAHA.119.044578). These new analyses also highlight another attractive feature of dapagliflozin and, apparently, the entire class of SGLT2 inhibitors: They “ ‘play well with others’ when it comes to overlapping intolerances that often limit (either in reality or in perception) optimization of GDMT [guideline-directed medical therapy]. Although SGLT2 inhibitor therapy may lead to volume depletion and require adjustment of diuretics, the SGLT2 inhibitors generally lack some of the other dose-limiting adverse effects (such as renal dysfunction, hyperkalemia, and hypotension) that can make aggressive up-titration of GDMT problematic, particularly in older patients or those with more advanced disease,“ wrote Dr. Felker, professor of medicine at Duke University in Durham, N.C. “We stand at the beginning of a new era of ‘quadruple therapy’ for HFrEF with beta-blockers, an angiotensin receptor neprilysin inhibitor, mineralocorticoid receptor antagonists, and SGLT2 inhibitors,” he concluded.

A version of this article also appears on Medscape.com

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