Assessment of the use of the age- and sex-specific United States population as a control group for analysis of survival in coronary artery disease

An economic analysis of strategies for the use of contrast media for diagnostic cardiac catheterization

A decision tree model was used to estimate the incremental cost per quality-adjusted life year (QALY) of low- as opposed to high-osmolality contrast media for cardiac angiography. Analyses were done from the viewpoints of a third-party payer and society using data from a randomized trial and the literature. Assuming low-osmolality media reduce the risk of myocardial infarction and stroke, the incremental cost per QALY gained with these media is $17,264 in high-risk or $47,874 in low-risk patients for a third-party payer. From a societal viewpoint, the corresponding costs are $649 and $35,509. These estimates are sensitive to the cost and volume of the contrast medium employed and to the estimate of reduction in severe adverse events with low-osmolality media. The authors conclude that, in the context of restricted budgets, limiting the use of low-osmolality media to high-risk patients is justifiable, as the incremental cost per QALY in high-risk patients may be reasonable and it is not certain that low-osmolality media prevent severe or fatal events. A considerable reduction in the cost per QALY gained is possibly by minimizing the volume of contrast medium used.

Long-term relative survival rates after heart valve replacement

The calculation and comparison of relative survival rates after interventional studies is a method that permits correction for important demographic variables, thereby adjusting for the "background mortality" in the general population. Long-term relative survival rates were analyzed in a consecutive series of 2,805 Swedish patients who, on the basis of clinical symptoms, underwent aortic valve replacement (n = 1,741), mitral valve replacement (n = 792) and double (aortic plus mitral) valve replacement (n = 272) between 1969 and 1983. The follow-up period, which closed August 1, 1985, included 100% of patients and covered 16,822 patient-years. Autopsy was performed in 75% of all deaths. The results underscore previously well known differences between the long-term survival after aortic valve replacement and mitral or double valve replacement, whereas no differences were noted between mitral and double valve replacement. Within the subgroup undergoing aortic valve replacement, analysis of relative survival rates disclosed a highly significant (p less than 0.001) difference between patients operated on for aortic stenosis and those operated on for aortic regurgitation, representing a mortality rate more than twice as high in the latter group. This difference was of much lesser magnitude when analyzed in the standard (actuarial) way. With a low (less than 2.5%) operative mortality rate for patients undergoing isolated elective aortic valve replacement in the current era and with an acceptable incidence of late valve-related death (5.2% at 10 years), these results may justify aortic valve replacement earlier in the course of chronic aortic regurgitation to prevent irreversible myocardial damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Heart valve replacement in septuagenarians

Heart valve replacement was performed on 208 patients aged 70-80 years--aortic (AVR) in 172, mitral in 20 and both valves in 16 cases. All valves were of Björk-Shiley type, and all but six patients received maintenance oral anticoagulant therapy. The 100% follow-up comprised 744 patient-years (mean 4.0 years). The early mortality was 9.6% and was related to the complexity and urgency of surgery: After elective AVR for pure aortic stenosis the rate was 3.9%. Actuarial survival (early mortality excluded) was 79% at 5 years and 73% at 8 years overall, and 87% and 80% after AVR for stenosis. In the AVR group the relative (age- and -sex-adjusted) survival rate indicated a normalized survival pattern after the first year, with 87%, 'cure' rate (early mortality included), and the incidence of thromboembolism and of fatal bleeding complications equalled figures for younger patients. Mechanical heart valve implantation and maintenance anticoagulation thus seems to be safe treatment even in elderly patients, and eliminates need for valve re-replacement due to bioprosthetic degeneration.

Assessment of coronary bypass surgery and percutaneous transluminal coronary angioplasty

Coronary bypass surgery developed as another in a line of surgical procedures dating back more than 60 years. The medical profession at first assessed this procedure with time-honored anecdotal techniques. Gradually, for a variety of reasons, improved methods of comparisons worked their way into assessments of bypass surgery. Randomized controlled trials met resistance but have been very influential. Assessment of percutaneous transluminal coronary angioplasty has benefited from the knowledge generated during the last 25 years, but clinicians have been slower to apply the most advanced techniques.