New heart treatment tested at Vanderbilt
It’s been 10 years since a new intravenous drug for congestive heart failure has been approved for acute therapy.
Doctors used the current IV medications to aid acutely ill patients in life-threatening situations with some success, despite the potential side effects.
Until now, there were few choices available to deal with one of the most expensive medical problems in the country. But Dr. Don B. Chomsky, assistant professor of Medicine, hopes to change that for Vanderbilt University Medical Center patients.
The most common medications for the treatment of congestive heart failure are intravenous diuretics to remove fluid buildup; inotropes are used as a cardiac stimulant to drive the heart to pump; and vasodilators dilate the blood vessels to allow a weakened heart to pump efficiently.
Although these drugs work well for patients, they do so with potential problems. Inotropes are effective, but they increase the risk of heart rhythm abnormalities, which can be fatal. Vasodilators, most specifically nitroprusside, are very effective. But necessary dosage titration and constant monitoring require patients to be admitted into the intensive care unit.
“There is some concern that using inotropes are like whipping a dying horse,” Chomsky said. “Its use exhausts the heart muscle and can precipitate fatal heart rhythms. So far, vasodilators have been the ideal agent for treatment, but the utilization is virtually 5 percent or less because of the downsides.”
With so many advancements in the treatment of heart-related conditions in the last decade, the question arises: why is there a lag in developing drugs to treat the No. 1 cause for hospitalization in the United States?
“Researchers were not focused on improving the management of patients in the hospital,” Chomsky said. “The focus was on long-term oral medications for use outside of the hospital setting. The therapies that exist are often adequate, so there was not a huge desire to improve them.”
Natrecor is the first IV medication to surface for the treatment of acute heart failure patients.
Because Natrecor, also known by the generic name Neseritide, is not truly an inotrope, there are no concerns of further deterioration of the heart muscle and there are no significant heart rhythm abnormalities. There is no need to titrate or constantly adjust the doses of this medication as seen with vasodilators. It therefore decreases the need for more expensive hospitalization and monitoring.
“This is a single dose infusion,” Chomsky said. “At the current approved dose, it not only enhances fluid removal, it also works as a vasodilator to lower the pressure in both the heart and lungs.
“The only drawback is that it is expensive. The question becomes who should we reserve this therapy for.”
Vanderbilt is one of 40 hospitals nationwide admitting patients into a double-blinded study to assess this question. Half the patients will receive standard treatment with IV diuretics, and half will receive a combination of standard therapy and Natrecor. The national enrollment goal is 500 patients. Vanderbilt hopes to enlist up to 20 patients.
“There is no doubt that this is an effective therapy that improves cardiac systems rapidly in hospitalized congestive heart failure patients,” Chomsky said. “But because of the cost of the drug there is a need to better determine what patients need it, and at what point in the therapy it is added.
“The average hospital stay for these patients is four to seven days at a cost of at least $7,000. Keep in mind that the health-related and economic costs of this condition are huge.
“The ultimate goal is to change many of the hospitals’ heart failure treatment to a 23-hour stay, which is not considered an admission. If we can lessen both the health care and economic burden, then we have come a long, long way in treatment.”
Currently, Chomsky has enrolled five patients in the study.