Keeping the Pressure Down in Patients With Type 2 Diabetes and Peripheral Artery Disease
Intensive blood-pressure lowering reduced the risk of ischemic events in the small population of patients with diabetes and peripheral artery disease, according to a report from Colorado researchers in this week’s issue of Circulation (Circulation. 2003;107:753–756).
Scientists led by Philip S. Mehler, MD, of the University of Colorado Health Sciences Center in Denver, monitored 950 subjects in the Appropriate Blood Pressure Control in Diabetes (ABCD) study for 5 years. All patients had type 2 diabetes and 480 were considered to have normal blood pressures with baseline diastolic pressure of 80 to 89 mm Hg. Those who received placebo had a mean blood pressure of 137±0.7/81±0.3 mm Hg over the last 4 years of the study. By contrast, patients randomized to intensive treatment maintained a 4-year blood pressure of 128±0.8 / 75±0.3 mm Hg. Peripheral artery disease was identified in 53 patients.
In patients with peripheral artery disease who received intensive treatment, 13.6% (3 patients) suffered a cardiovascular event compared with 38.7% (12 patients) on placebo—even though members of both groups had what is considered normal blood pressure.
The authors concluded that peripheral artery disease “is a common presentation of atherosclerosis and is also a strong independent predictor of future cardiovascular ischemic events. Our results suggest that blood pressure lowering in normotensive type 2 diabetic patients with PAD [peripheral artery disease] is particularly effective in preventing adverse cardiovascular events. Intensified efforts to treat hypertension aggressively in patients with PAD therefore seem justified, particularly because diabetes is a strong predictor of a worse natural history for PAD, with more patients progressing to ischemic ulceration. Additional longitudinal studies of intensive blood pressure control in patients with PAD should be conducted to clarify this association further.”
Statins in Peripheral Artery Disease: a Positive Combination
Taking statins appears to improve function in the legs of people with and without peripheral artery disease—an effect independent of cholesterol levels and other confounding factors, according to a multicenter study published in this week’s issue of Circulation (Circulation. 2003;107:757–761).
Participants included 392 men and women with an ankle brachial index <0.90 and 249 with an ankle brachial index of 0.9 to 1.5. Patients were scored on a 6-minute walk distance and a 4-meter walking velocity. There was also a combined summary performance score involving walking speed, standing balance, and time for 5-repeated chair rises that went from 0 to 12 with 12 being the best. All scores were adjusted for age, sex, ankle brachial index, comorbidities, education level, medical insurance status, cholesterol, and other confounding factors.
The researchers led by Mary McGrae McDermott, MD, of Feinberg School of Medicine at Northwestern University in Chicago, Ill, determined that participants taking statins walked farther in 6 minutes (1276 feet versus 1218 feet), faster (0.93 versus 0.89 meters/second), and a higher summary performance score (10.2 versus 9.4) than those who were not taking the cholesterol-lowering drugs. No positive association was found for taking aspirin, ACE inhibitors, vasodilators, or β-blockers. The positive associations with statin use were attenuated when adjusted against the level of C-reactive protein but remained statistically significant for walking velocity and the summary performance score.
The researchers concluded: “Statin use is associated with superior leg functioning compared with no statin use, independent of cholesterol levels and other potential confounders. These data suggest that non–cholesterol-lowering properties of statins may favorably influence functioning in persons with and without peripheral artery disease.”
An Emergency Room Plan Can Save Lives of Those With Cocaine-Related Heart Problems
Observing low- to medium-risk patients with cocaine-associated chest pain in the emergency room for 9 to 12 hours and the use of protocol-driven care can safely identify those patients who can be released from the emergency department safely, according to researchers who monitored 344 consecutive patients who arrived at the hospital with cocaine-related problems (N Engl J Med. 2003;348:510–517).
The study involved scientists from a variety of centers and was led by emergency physician Jim Edward Weber, DO, of the University of Michigan School of Medicine. Patients who had normal levels of troponin I without new ischemic changes in their electrocardiograms and who had no other heart complications, such as abnormal rhythms, heart attack, or recurrent symptoms during their period of observation, were discharged from the unit. A total of 42 patients were admitted to the hospital for further treatment and observation.
None of the remaining 302 patients who were discharged died of a heart-related event during the 30-day follow-up period. Only 4 of 256 patients for whom detailed follow-up data were available had a heart attack in the subsequent study. All events occurred in patients who continued to use cocaine.
According to Dr Weber, the risk of a heart attack in the first hour after cocaine use is 24 times that of a normal person. Overall, cocaine users have a seven-fold increased risk of heart attack compared with those who do not use cocaine, he said. He estimated that as many as one-fourth of heart attacks in people ages 18 to 45 are related to use illegal use of cocaine. Dr Weber said he thought that the plan used in the study could be used nationwide.
“While these findings come from a population with high cocaine use, and thus a high incidence of cocaine-related heart effects, this standard of care could be used in any hospital,” said Judd Hollander, MD, Professor of Emergency Medicine at the University of Pennsylvania, who has led other studies of cocaine-related heart disease. “But studying this population means we were able to get results from a large number of patients relatively quickly.”
The new study should help doctors decide who needs the most intensive heart care, Dr Weber said. “This is a serious issue nationwide, with little consistency in treatment from hospital to hospital, and care for these patients costs $83 million just in hospitalization annually. We devised this care standard to try to optimize care while containing costs.”
Studies Take Different Routes to Reducing Nephrotoxicity From Contrast Agents
European researchers found that the use of an iso-osmolar, dimeric nonionic contrast medium called iodixanol reduced the risk of nephrotoxicity in high-risk patients undergoing angiography (N Engl J Med. 2003;348:491–499), and Hong Kong researchers found an antioxidant called acetylcysteine provided similar protection in similar patients undergoing the same procedure (JAMA. 2003:289:553–558).
In the study that appeared in the February 6, 2003, issue of the New England Journal of Medicine, researchers led by Peter Aspelin, MD, PhD, for the Nephrotoxicity in High-Risk Patients Study of Iso-Osmolar and Low-Osmolar Non-Ionic Contrast Media (NEPHRIC) Study Investigators, reported on 129 patients with diabetes who had serum creatinine concentrations of 1.5 to 3.5 mg per deciliter who underwent coronary or aortofemoral angiography. Patients were randomized to an iso-osmolar, dimeric nonionic contrast medium iodixanol or a low-osmolar, nonionic, monomeric contrast medium iohexol.
Serum creatinine concentrations increased significantly less in the patients who received the iodixanol, the researchers reported. During the 3 days after the procedure, the peak increase in creatinine was 0.13 mg per deciliter in the iodixanol group and .55 mg per deciliter in the iohexol group. The researchers concluded: “Nephropathy induced by contrast medium may be less likely to develop in high-risk patients when iodixanol is used rather than a low-osmolar, nonionic contrast medium.”
In the study in the February 5, 2003, issue of the Journal of the American Medical Association, researchers from Hong Kong and Australia reported on the use of the antioxidant acetylcysteine on the day before and the day of an elective angiography. A total of 200 patients were randomized to receive acetylcysteine or placebo. All patients had moderate renal insufficiency. All received the low osmolality contrast agent iopamidol.
Twelve patients in the placebo group and four in the treatment group developed a >25% increase in serum creatinine within 48 hours after receiving the contrast agent. The researchers led by Jay Kay, MBBS, from Grantham Hospital in Hong Kong, found that serum creatinine was consistently lower in the group that received acetylcysteine than in the control group. They concluded that acetylcysteine protected patients with renal dysfunction from deterioration caused by contrast medium. The treatment, they said, had minimal adverse effects and costs little.