Recent study results showed that a novel potential therapy for heart failure was effective during exercise, building on an earlier study that showed its effectiveness at rest.
Study results recently published in Journal of the American College of Cardiology: Heart Failure build on novel research investigating the efficacy of blocking the splanchnic nerve to treat patients with heart failure.
The study, which was led by former DCRI fellow Marat Fudim, MD, MHS, included 15 patients who underwent a temporary medication-induced splanchnic nerve blockage and required them to complete an exercise twice—once prior to the blockage, and once after the blockage. After the blockage, patients had lower pressure in the heart, their hearts were able to circulate more blood, and patients were able to achieve more work with exercise than before.
Fudim explained the mechanism this way: When healthy people exercise, blood moves from the abdomen where it is stored to the chest. However, this process often presents problems for patients with heart failure, a condition which is characterized by stiff vessels and heart accompanied by an overabundance of fluid. When more fluid moves to the chest, it triggers high pressure in the lungs, which is why people who have heart failure often experience shortness of breath when they exercise.
However, when the splanchnic nerve is blocked, fluid is shifted into the belly, thereby lowering pressure in the chest and the heart. The idea for this new concept and therapy in heart failure is founded in parts of the literature around cancer, where this type of blockage is a commonly used treatment for pain. Anesthesiologists must give these patients fluid before the blockage, or their blood pressure will drop too low. Fudim saw this significant drop in pressure, which occurs as a result of fluid shifting away from the heart, as an opportunity for his field.
In 2018, during his DCRI fellowship, Fudim led a study that showed the effectiveness of the nerve block in eleven patients at rest. For this most recent study, the team wanted to determine if this effectiveness would extend to patients who were exercising.
In the new study, patients were asked to perform a leg exercise in the supine position until they reached peak exertion. Following the splanchnic nerve block, patients had lower pressure at rest and during exercise than prior to the block. Further, they were able to exercise harder (at a higher difficulty level) and their heart achieved a higher output at peak exercise.
“It was great to see that, despite patients being tired from their first round of exercise, the splanchnic nerve block had such an effect that they were actually able to exercise harder the second time around,” Fudim said. “Patients also reported feeling differently before and after the block. When asked why they stopped exercising before the nerve was blocked, patients were likely to say they were short of breath. When asked the same question after the nerve was blocked, more patients said their legs were tired but fewer reported shortness of breath. This anecdotal evidence supports our findings that blocking the splanchnic nerve improved measures related to exercise even for these very sick patients.”
In the future, Fudim plans to continue his investigations into this novel potential treatment by studying the nerve blockage’s impacts on different types of patients in different scenarios. Although the effects of the splanchnic nerve block are temporary, Fudim is investigating how the block could be sustained over a long span of time to treat a chronic condition like heart failure.
This study was supported by the Translating Duke Health Initiative. Additional DCRI collaborators include Adam DeVore, MD, MHS; Joseph Rogers, MD; Sunil Rao, MD; David Kong, MD; Schuyler Jones, MD; Cynthia Green, PhD; Michael Felker, MD; Adrian Hernandez, MD, MHS; and Manesh Patel, MD.