Sickest Minority of Heart Attack Patients Constitute Majority of In-Hospital Deaths
An international "snapshot" of almost 5,600 heart attack patients has shown that while those who also have heart failure and/or a weak left pumping chamber represent about 42 percent of total heart attack patients, they account for 81.5 percent of the deaths in hospital, according to Duke University Medical Center cardiologists and their international colleagues.
These findings are important, the researchers said, because they clearly identify those heart attack patients who are at highest risk for death. Just as importantly, the researchers also found that this group of patients does not adequately receive proven therapies, both medical and procedural, that could improve their chances for survival.
The results of the Duke analysis were presented today (March 30, 2003) by Duke cardiologist Eric Velazquez, M.D., during the 52nd annual scientific sessions of the American College of Cardiology.
"This sizeable minority of heart attack patients appears to be at the highest risk for dying of their heart attack while in the hospital," Velazquez said. "The message for cardiologists is to identify these patients and aggressively treat them with therapies that have proven to be effective.
"We need to do a better job identifying and treating these patien" Velazquez said. "They are the sickest heart attack patients and they have the most to gain from aggressive treatment."
Heart failure is a condition marked by abnormal heart function that leads to symptoms of lung congestion and an inability to meet the metabolic demands of the body. Patients whose left ventricle -- the main pumping chamber of the heart -- pumps at less than 40 percent of its strength have what is termed left ventricular systolic dysfunction (LSVD). LVSD can be, but not always, a cause of heart failure.
Patients with heart failure and/or LVSD are not usually enrolled in typical clinical trials involving heart attack because they are believed to be too sick, Velazquez said.
To gain better insights into these patients, Velazquez organized a separate patient registry in conjunction with an ongoing clinical trial on the effect of valsartan -- an angiotensin II receptor blocker (ARB) -- on patients with HF and/or LVSD after a heart attack. Valsartan is currently approved for lowering blood pressure.
The overall trial, dubbed VALIANT (VALsartan In Acute myocardial iNfarcTion) enrolled over 14,500 patients in 24 countries.
To gain a "snapshot" of contemporary heart attack patients worldwide, Velazquez gathered additional data on 5,592 consecutive MI patients enrolled from 1999-2001. Of those patients, 2,352 (42 percent) also suffered from heart failure and/or LVSD and were theoretically eligible for the VALIANT trial.
"What we ended up with was a real-world registry of patient data," Velazquez said. "These patients are a significant minority of patients whose effect on overall in-hospital morbidity and mortality appears to be profound.
"The overall in-hospital death rate was 6.9 percent," Velazquez continued. "However, the patients with heart failure and/or LVSD had a 13.1 percent death rate, compared to 2.4 percent for the other patients."
Also, the heart attack patients with heart failure and/or LVSD averaged 12 days in the hospital, compared to 7.6 days for the other group.
In addition to following how these patients fared during their hospitalization, Velazquez also gathered data on different treatments used on these patients.
"Only 34.2 percent of these patients received angiotensin-converting enzyme (ACE) inhibitors and 58 percent received beta-blockers within the first 24 hours," Velazquez continued. "These medicines have been proven in clinical trials to improve mortality rates. As far as revascularization procedures, 31.4 percent received angioplasty and 11 percent underwent coronary artery bypass surgery.
"This registry sets the stage for VALIANT by reinforcing the critical need to identify the best strategies to treat this high risk group of MI patients," Velazquez said. "We know that ACE inhibitors improve mortality for heart attack patients, and we are still determining the role of ARBs."
The goal of VALIANT is to determine whether or not valsartan can reduce the mortality of heart attack patients with heart failure and/or LVSD. It will be tested alone and in conjunction with captopril, an ACE inhibitor.
VALIANT is supported by Novartis Pharmaceuticals, East Hanover, N.J. and the principal investigator is Marc Pfeffer, M.D., Harvard University Medical School and Brigham & Women?s Hospital, Boston.
CHICAGO - DukeMed News