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Biomedical subjects

J L Ritchie

Publications and source records attributed to J L Ritchie.

At least 37 records · Page 2Linked to original sources
PubMed1998

A comparison of percutaneous transluminal coronary angioplasty in the Department of Veterans Affairs and in the private sector in the State of Washington.

Coronary angioplasty is performed > 1,000 times daily in a variety of health care settings in the public and private sectors in the USA. How outcomes for this procedure differ in the Department of Veterans Affairs and the private sector is unknown. The purpose of this study was to compare outcomes of coronary angioplasty performed in hospitals in the Department of Veterans Affairs and the State of Washington. This study used administrative data from the Department of Veterans Affairs patient treatment file (n = 8,326) and the State of Washington episode of illness file (n = 6,666) and included men who underwent coronary angioplasty in 1993 and 1994. Outcomes included (1) in-hospital mortality and mortality at 10 and 30 days after hospital admission, and (2) the use of coronary artery bypass surgery at similar intervals. Patients with a principal diagnosis of acute myocardial infarction were analyzed separately. Men in the Department of Veterans Affairs had more comorbid conditions than their counterparts in Washington State, and the length of hospital stay was longer in the former group. After using logistic regression to adjust for patient differences, mortality rates for the 2 groups of patients with acute myocardial infarction were similar, although bypass surgery was used more frequently in patients in Washington State. For patients without myocardial infarction, hospital and 10-day mortality did not differ with respect to health care system, and the use of bypass surgery subsequent to angioplasty was similar. In the Department of Veterans Affairs, most hospitals had low institutional caseloads (< 150 procedures per year), whereas > 40% of Washington State hospitals performed > or = 300 procedures per year. Although there were greatly differing institutional caseloads, mortality and the need for early bypass surgery were similar in the 2 systems.

Adult↗
PubMed1998

Coronary angioplasty outcomes in the Healthcare Cost and Utilization Project, 1993-1994.

It is estimated that >400,000 percutaneous transluminal coronary angioplasty (PTCA) procedures are performed in the Unites States annually. This study reports patient characteristics and outcomes for 163,527 PTCAs performed in 214 hospitals in 17 states from 1993 to 1994. These hospitals were a 20% random sample of hospitals in the Healthcare Cost and Utilization Project, which was designed to reflect hospitalization in the United States, generally. Cases with International Classification of Diseases, 9th Revision, Clinical Modification procedure codes 36.01, 36.02, and 36.05 were defined as PTCA and were categorized as to whether acute myocardial infarction (AMI) was the principal discharge diagnosis. The average age of 44,270 AMI discharges (27%) was 62 +/- 12 years and that of 119,257 no-AMI cases (73%) was 64 +/- 11 years; 1/3 of both groups were women, 88% were white, and almost 90% had Medicare or private insurance as the primary payer. The states contributing the most cases were Florida (26%), California (12%), and Wisconsin (10%). Hospital mortality was 1.7% overall and was 3.8% for AMI and 0.8% for no-AMI cases. Bypass surgery performed during the same admission was 3.4% overall and was 4.5% and 3.0% for AMI and no-AMI cases, respectively. Multivariate analysis showed that advanced age, diabetes, female gender, and Medicaid payer status were associated with increased risk of mortality. National estimates from this 20% sample indicate that >850,000 PTCAs were performed in the 2 years, with 452,319 cases estimated for 1994. In 1994 there were an estimated 2,789 deaths and 9,903 bypass surgeries in the no-AMI subset of 327,856 procedures. For the AMI group of 124,463 procedures, there were 4,486 deaths and 5,799 bypass surgeries in 1994. This study of PTCA outcomes contains the largest number of cases as well as the most representative sample reported to date.

Angioplasty, Balloon, Coronary↗
PubMed1998

Health outcomes associated with beta-blocker and diltiazem treatment of unstable angina.

OBJECTIVE: We compared long-term health outcomes associated with beta-adrenergic blocking agents and diltiazem treatment for unstable angina. BACKGROUND: No long-term data have been published comparing these two antianginal treatments in this setting. METHODS: Eligible veterans were discharged from the Veterans Affairs Puget Sound Health Care System (VAPSHCS), Seattle Division, between October 1989 and September 1995 with an unstable angina diagnosis and were prescribed monotherapy beta-blocker or diltiazem treatment at discharge. Medication data were collected from medical records and computerized VAPSHCS outpatient pharmacy files. Follow-up death and coronary artery disease rehospitalization data were collected through 1996. Proportional hazards regression compared survival among diltiazem and beta-blocker users, controlling for patient characteristics with propensity scores. RESULTS: Two hundred forty-seven veterans (24% on beta-blockers, 76% on diltiazem) were included in this study. There were 54 (22%) deaths during an average follow-up of 51 months. After propensity score adjustment, there was no difference in risk of death comparing diltiazem to beta-blocker treatment (hazards ratios [HR] 1.1; 95% confidence interval [CI] 0.49 to 2.4). Among Washington residents (n=207), there were 146 (71%) coronary artery disease rehospitalizations or deaths during follow-up. After adjustment, there was a nonsignificant increase in risk of rehospitalization or death associated with diltiazem use (HR 1.4; 95% CI 0.80 to 2.4). For both analyses, similar risks were found among veterans without relative contraindications to beta-blockers. CONCLUSIONS: We found no survival benefit of diltiazem over beta-blocker treatment for unstable angina in this cohort of veterans.

Adrenergic beta-Antagonists↗
PubMed1995

The association of hospital volumes of percutaneous transluminal coronary angioplasty with adverse outcomes, length of stay, and charges in California.

The objective of this study was to examine whether hospital volumes of percutaneous transluminal coronary angioplasty (PTCA) are associated with adverse outcomes (coronary artery bypass graft surgery after PTCA and/or in-hospital mortality), post-PTCA length of stay (LOS), and hospital charges. Discharge data for 24,856 patients undergoing PTCA in 1989 from 110 California hospitals were analyzed. Regression analysis was used to adjust patient discharge data for risk factors. Actual and predicted adverse outcomes, LOS, and charges were compared for hospital volume categories (using 95% confidence intervals). Rates of adverse outcomes were significantly higher than expected in low-volume hospitals (< 201 PTCAs) and significantly lower than expected in high-volume hospitals (> 400 PTCAs). The results were similar for LOS and charges, although the results for charges were less conclusive. The associations of volumes and outcomes were generally consistent for both unadjusted and adjusted analyses, for patients with and without principal diagnoses of acute myocardial infarction, and using different methods and functional forms. Given this association between hospital volumes of PTCA and outcomes, future research should assess the underlying causes of this association and whether limiting the use of low-volume facilities would improve outcomes.

Angioplasty, Balloon, Coronary↗
PubMed1994

Evaluation of annexin V as a platelet-directed thrombus targeting agent.

Annexin V is a human phospholipid binding protein (M(r) 36,000) that binds with high affinity to activated platelets in vitro. We studied the biodistribution and thrombus binding of annexin V in rabbit and swine models of fully occlusive arterial thrombi formed 1-2 h prior to injection of annexin V. Iodinated annexin V was cleared from blood in a rapid early phase (t1/2 = 6.4 min, 76% of radioactivity) and a slower late phase (t1/2 = 71 min, 24% of radioactivity). Organ uptake was highest in the kidney and spleen and lowest in heart and skeletal muscle. Thrombus/blood uptake ratios were (mean +/- SEM): 6.39 +/- 1.80 for rabbit iliac artery, 6.97 +/- 1.45 for swine carotid artery, and 7.68 +/- 1.70 for swine femoral artery (all p values < 0.01 versus control artery); a control protein, ovalbumin, showed an uptake ratio of 0.59 +/- 0.08 in swine femoral artery thrombi. These results indicate that annexin V is useful as an agent for selective targeting of platelet-containing thrombi.

Animals↗