Thrombolytic Tx in Kidney Patients
Thrombolytic therapy is delayed in patients with kidney disease who develop MI, which is “particularly unfortunate” in this patient population because of their large burden of cardiovascular disease and high CVD mortality, according to Britt B. Newsome, M.D., of the Birmingham (Ala.) Veterans Affairs Medical Center, and associates.
The researchers analyzed data from 109,169 MI patients who were treated at more than 6,000 U.S. acute-care hospitals, and found that “door-to-needle time” increased as severity of kidney disease worsened.
They also found that patients with kidney disease were no more likely than those with normal kidney function to develop bleeding complications from thrombolytic therapy (Am. J. Kidney Dis. 2005;46:595–602).
The treatment delay may be due to clinicians' perception that kidney patients are more frail, less likely to benefit from treatment, or more likely to develop adverse effects, particularly bleeding complications, than other patients. But the study results suggest that such concerns are not warranted.
This study also disproved another possible explanation for the treatment delay, namely that patients with kidney disease have more comorbidities than other patients, which complicates their medical care and increases the time needed to make treatment decisions. Also, the subjects with kidney disease did have more comorbidities, but comorbidities did not correlate with treatment delays, the investigators noted.
Statins: Benefits Outweigh Hazards
Statin therapy doesn't raise the risk of cancer or any specific cause of death, and it carries an extremely low risk of rhabdomyolysis, according to investigators in the Cholesterol Treatment Trialists' collaborative study.
The CTT collaborators will report on periodic metaanalyses of morbidity and mortality data from all the large randomized trials of lipid therapies. In the first such report, which involved 14 statin trials, the CTT found a direct linear relationship between reductions in LDL cholesterol level and reductions in coronary and other vascular events (Lancet 2005;366:1267–77).
Although previous research had suggested that statin use might raise the risk of nonvascular causes of death, particularly cancer, this concern was not borne out in the metaanalysis.
The safety of statins was further confirmed by the finding of an excess risk of rhabdomyolysis of only 0.01% after 5 years of treatment.
“The potential hazards of lowering LDL cholesterol with these statin regimens seemed to be extremely small in relation to the clear benefits in many circumstances,” the CTT researchers said.
Endocarditis Rate Remains Stable
The incidence of infective endocarditis hasn't changed over the past 30 years in many areas of the United States, and Streptococci—not Staphylococcus aureus—continue to be the most common cause of infection, reported Imad M. Tleyjeh, M.D., of the Mayo Clinic, Rochester, Minn., and associates.
In a community surveillance study, all 107 cases of infective endocarditis treated in one Minnesota county between 1970 and 2000 were reviewed. The incidence remained stable throughout the study, with annual rates ranging from 5.0 to 7.0 cases per 100,000 person-years (JAMA 2005;293:3022–8).
Other researchers have reported an increasing frequency of S. aureus endocarditis or a drop in streptococcal endocarditis, “leading to a general consensus that S. aureus has surpassed viridans group streptococci as the leading cause” of the infection.
“In contrast, we found that viridans group streptococci continue to be the most common cause of infective endocarditis in the study population and that its incidence rate is approximately twice that of S. aureus,” they noted.
Drug Treatment Mismatched in HF
Among patients hospitalized with heart failure, those who are at the highest risk of death are the least likely to be given drugs of proven benefit, according to Douglas S. Lee, M.D., Ph.D., of the University of Toronto, and his associates.
They assessed drug treatment in relation to predicted 1-year mortality risk, using data from a study of 1,418 heart-failure patients treated at 103 acute-care hospitals across Ontario.
The number of prescriptions written at hospital discharge for ACE inhibitors, angiotensin II-receptor blockers, and ?-adrenoreceptor antagonists decreased as mortality risk increased, the investigators said (JAMA 2005;294:1240–7).
The mismatch between mortality risk and drug prescriptions persisted even in patients who had no perceived contraindications to the drugs and no life-limiting comorbidities that could confound a risk-benefit assessment. It seems likely that clinicians undertreated these patients because either they didn't appreciate the benefits of therapy or they mistakenly believed that high-risk patients are more susceptible to the medications' adverse effects, Dr. Lee and his associates said.