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J L Ritchie

Publications and source records attributed to J L Ritchie.

At least 19 recordsLinked to original sources
PubMed2001

Comparison of short-term outcomes following coronary artery stenting in men versus women.

This study sought to determine whether women have more adverse in-hospital outcomes after percutaneous transluminal coronary angioplasty (PTCA) and stenting compared with men. There is still controversy regarding whether female gender is an independent predictor of mortality after PTCA. No study has examined gender differences in outcomes following the dissemination of stenting. Data were obtained from the Nationwide Inpatient Sample. In 1997, there were 118,548 angioplasties (36% occurred in women and 59% involved placement of stents). Outcomes included same-admission mortality and coronary artery bypass grafting (CABG). Analyses were performed separately for patients with and without acute myocardial infarction (AMI). In 1997, women had a roughly twofold higher mortality than men in every comparison group, including conventional PTCA alone and stents. Mortality rates after stenting were 4.0% for women and 2.0% for men with AMI (p <0.0001), and 1.1% and 0.5%, respectively, for patients without AMI (p <0.0001). The adjusted odds ratios were 1.47 (95% confidence interval 1.23 to 1.75), and 1.65 (95% confidence interval 1.33 to 2.04), respectively. Similarly, following stenting, women had significantly higher CABG rates than men in both the AMI (1.6% vs 1.2%, p = 0.025) and no AMI groups (1.5% vs 1.0%, p <0.0001). After multivariate adjustment, the results retained significance in the no AMI setting, whereas there was a trend toward significance in the AMI group. This study demonstrates that, despite improved overall outcomes in patients who received stents, women who underwent stenting had higher rates of same-admission mortality and CABG compared with men. Furthermore, it confirms that female gender is an independent predictor of mortality after conventional PTCA.

Aged↗
PubMed2001

Comparison of outcomes of coronary stenting versus conventional coronary angioplasty in the department of veterans affairs medical centers.

Although the short-term benefits of stent deployment have been established, less is known about long-term outcomes. This study compares short- and long-term outcomes in veterans undergoing stenting and conventional coronary angioplasty. We used Department of Veterans Affairs databases to identify 27,224 veterans who had undergone percutaneous coronary intervention (PCI) in Veterans Affairs medical centers between October 1994 and September 1999. Patients were classified according to whether they had acute myocardial infarction (AMI) as the principal diagnosis. Baseline characteristics were similar in the stent and conventional groups. In AMI, hospital mortality was 2.9% for those with stents and 4.8% for those who underwent conventional coronary angioplasty (p <0.0001), whereas for patients without AMI, hospital mortality was similar (1.2% vs 1.4%, p = 0.12). For AMI, same-admission bypass surgery rates were lower in the stent group (0.7% vs 3.2%, p <0.0001) and in the group without AMI (1.2% vs 3.3%, p <0.0001). Two-year survival was better for stenting in veterans with (90% vs 88%, p = 0.006) and without (92% vs 91%, p = 0.008) AMI. For AMI, 2-year rehospitalization rates for PCI (10% vs 13%, p <0.0001), coronary artery bypass surgery (4% vs 6%, p <0.0001), and unstable angina (17% vs 23%) were lower for those who had stenting. In the no-AMI group, 2-year rehospitalization rates for PCI (14% vs 17%, p <0.0001), coronary artery bypass surgery (5% vs 8%, p <0.0001), and unstable angina (22% vs 29%, p <0.0001) were lower in the stent group. Veterans who underwent stenting had lower hospital mortality, reduced rates of same-admission bypass surgery, marginally better survival, and lower rates of rehospitalization than their counterparts who had conventional coronary angioplasty.

Adult↗
PubMed2001

Racial differences in outcomes of veterans undergoing percutaneous coronary interventions.

BACKGROUND: In the era of stenting relatively little is known about racial differences in the outcomes of percutaneous interventions (PCI). The purpose of this study was to determine whether there were racial differences with respect to short- and long-term outcomes in veterans undergoing PCI. METHODS: We used the national Department of Veterans Affairs (VA) patient treatment file to identify 24,625 African American and white veterans who had PCI in VA medical centers between October 1, 1994, and September 30, 1999. Baseline demographic characteristics were obtained, as was a measure of comorbidity. Short-term outcomes included hospital mortality and same-admission coronary artery bypass surgery, and long-term outcomes were vital status and rehospitalization. Multivariate statistical methods were used to adjust for patient differences when comparing both short- and long-term outcomes for African American and white veterans. RESULTS: African Americans were 11% of veterans, and in comparison with their white counterparts had more hypertension, diabetes, and acute myocardial infarction. African Americans less often underwent stenting (44% vs 49%), although hospital mortality (2.0% vs 1.9%) and same-admission bypass surgery (1.9% vs 2.2%) rates were similar. Two-year survival was 89% in African Americans and 91% in white veterans (P =.0014), and after adjustment for covariates African Americans had slightly higher mortality rates (hazard ratio 1.11, 95% confidence interval 1.05-1.17). At 2 years almost 61% of both African American and white veterans were rehospitalized for any reason. CONCLUSION: Short- and long-term outcomes for African American and white veterans undergoing PCI in VA medical centers were similar, although African Americans underwent stenting less often.

Black or African American↗
PubMed2001

Improved outcomes associated with stenting in the healthcare cost and utilization project.

Recent results from Medicare indicated that both hospital mortality and the use of same admission coronary artery bypass graft (CABG) surgery were lower in patients receiving stents, and that stenting did not alter the finding of improved outcomes at high volume centers. The purpose of this report is to compare outcomes in a national sample of patients of all ages receiving stents with those undergoing conventional balloon angioplasty. A second purpose is to evaluate the volume outcome hypothesis. This study included 100,318 angioplasties from 191 hospitals in 19 states; 43,966 (44%) involved stent placement. The major outcomes of interest were same admission hospital death and same admission CABG surgery. In comparison to patients with conventional angioplasty, patients receiving stents were younger, less often female and nonwhite, and had less diabetes and hypertension. In the group without infarction, hospital mortality was lower in the stent group (0.7% vs 0.9%, P = 0.01), as was the use of same admission bypass surgery (1.4% vs 2.7%, P < 0.0001). The same pattern was true for myocardial infarction; hospital mortality (2.7% vs 4.2%, P < 0.0001) and bypass surgery rates (1.6% vs 5.3%, P < 0.0001) were lower in the stent group. These results persisted after adjustment for important predictors of outcome. In general, outcomes were better in high volume centers, although in the stent group, there was no clear relationship between volume and outcome. These results support earlier findings that hospital mortality and particularly same admission surgery rates are lower with stenting. Although the volume outcome association for stenting was less clear in this study than in Medicare, these results do not mean that the fundamental volume outcome relationship has been changed by stenting.

Aged↗
PubMed2000

Outcomes of coronary angioplasty procedures performed in rural hospitals.

PURPOSE: To determine how many rural hospitals in the United States performed coronary angioplasty; to compare patient outcomes in rural and urban hospitals; and to assess whether outcomes were better in rural hospitals in which more procedures were performed. SUBJECTS AND METHODS: In 1996, among patients 65 years of age and older, 201,869 coronary angioplasties were performed in 996 hospitals that were included in the Medicare Provider Analysis and Review files. Geographic location was defined as rural or urban, according to U.S. Census Bureau criteria. Outcome variables were in-hospital death and coronary artery bypass surgery performed during the same admission. Hospital volumes were categorized as low (< or = 100 cases or fewer per year), medium (101 to 200 cases per year), or high (> 200 cases per year). RESULTS: Fifty-one rural hospitals accounted for 4% of all angioplasties performed. After angioplasty, in-hospital mortality was greater in rural hospitals (8.1% versus 6.4%, P = 0.001) among patients with acute myocardial infarction, but was not different for patients without infarction (1.4% versus 1.3%, P = 0.41). Coronary artery bypass surgery rates during the same admission were similar in rural and urban hospitals. In general, in-hospital mortality and same-admission surgery rates were lower in high-volume centers in both rural and urban areas. CONCLUSION: Although in-hospital mortality after angioplasty for acute myocardial infarction was worse in low- and medium-volume rural centers, overall outcomes in rural and urban hospitals were similar.

Aged↗
PubMed2000

Effect of tourniquet pressure and intra-individual variability on plasma fibrinogen, platelet P-selectin and monocyte tissue factor.

Small differences in levels of certain haemostatic components may be clinically significant. It is important therefore to eliminate potential sources of confounding variability. This study investigated the effect of removing tourniquet pressure prior to sample collection on plasma fibrinogen levels, platelet P-selectin and monocyte tissue factor expression. Blood was collected from the right arm under maintained tourniquet pressure and from the left arm following the release of pressure once the vein was sufficiently inflated for insertion of a needle. Whole blood was labelled within one hour of venepuncture to allow analysis of platelet P-selectin and monocyte tissue factor by flow cytometry. Plasma fibrinogen levels were analysed in samples stored at -70 degrees C, for all individuals at the end of the study using a method based on the Clauss technique. Intra-individual variability for each of the components was assessed by collecting samples under tourniquet pressure from four individuals on the same day on three consecutive weeks. Intra-individual variations were greater than assay CVs for all three components. There were no significant differences between the two tourniquet methods of collection for fibrinogen, P-selectin or tissue factor. In conclusion, there is no reason not to use a tourniquet during collection of blood for analysis of plasma fibrinogen, platelet P-selectin or monocyte tissue factor.

Adolescent↗
PubMed2000

Flow cytometry analysis of platelet P-selectin expression in whole blood--methodological considerations.

P-selectin is an adhesion molecule found in the alpha granules of platelets. Activation occurs in response to a range of inflammatory and thrombotic agents resulting in rapid up-regulation. Flow cytometry methods have recently been described for the analysis of platelet P-selectin expression in whole blood. While introducing these methods into our laboratory it was noted that expression could be stimulated, in vitro, in a number of ways. This study shows that red cell lysis, the anticoagulant K3 EDTA and the time elapse between blood collection and antibody labelling had statistically significant effects on P-selectin expression. Post-labelling fixation, with CellFIX, caused no significant effect. We conclude that blood for P-selectin analysis should be collected in sodium citrate and that red cell lysis and centrifugation should be avoided. When comparing samples, the time between collection and labelling should be standardized. The relatively high CV for the assay indicates that all samples should be labelled and analysed in duplicate with the mean level reported.

Adult↗
PubMed2000

The association between institutional primary angioplasty procedure volume and outcome in elderly Americans.

BACKGROUND: The association between greater procedure volume and improved patient outcome in cardiac procedures has been established in percutaneous transluminal coronary angioplasty (PTCA), coronary stent placement and coronary bypass surgery. The association between primary angioplasty volume and outcome has not been evaluated. METHODS: We evaluated the association between the volume of primary angioplasty procedures with short- and long-term outcome in 6,124 patients with documented acute myocardial infarction. Patients without shock on presentation treated with primary coronary angioplasty within 12 hours of hospital admission were selected from consecutive infarct patients included in the Cooperative Cardiovascular Project database. Patients were divided into quartiles based on the volume of primary PTCA procedures performed at their admitting hospital. RESULTS: The majority of United States (US) hospitals performed less than three primary PTCA procedures per month. Patients admitted to hospitals in the lowest volume quartile of primary PTCA had 31% higher 30-day mortality than those admitted to the highest volume quartile. After adjustment for baseline differences in patient characteristics, there was an association between admission to higher volume primary PTCA hospitals and lower 30-day mortality (odds ratio per volume quartile = 0.91; 95% confidence interval = 0.83-0.99). CONCLUSION: Eighty-two percent of US hospitals perform less than three primary PTCA procedures per month. In elderly Americans treated with primary PTCA, we observed an association between admission to higher volume hospitals and lower short- and long-term mortality. This association was independent of total PTCA volumes.

Aged↗
PubMed1999

Trends in the post-hospitalization medical treatment of unstable angina pectoris: 1990 to 1995.

This study provides data on post-hospitalization medication treatment trends for unstable angina between 1990 and 1995. We conducted an observational cohort study at the Veterans Affairs Puget Sound Health Care System (VAPSHCS). Computerized records of hospital discharges and cardiac catheterizations were used to identify unstable angina diagnoses among veterans between 1990 and 1995. Discharge medications issued within 90 days after discharge were ascertained from computerized outpatient pharmacy records. Of the 1,100 veterans discharged with unstable angina, 885 (80%) filled a prescription through the VAPSHCS within 90 days after discharge. Neither use of aspirin nor use of beta blockers increased between 1990 and 1995: overall use averaged 76% for aspirin (78% of those without potential contraindications) and 32% for beta blockers (36% of those without potential contraindications). Use of non-dihydropyridine calcium antagonists--primarily diltiazem--decreased from 57% to 40% (p <0.01), whereas use of dihydropyridine calcium antagonists increased from 12% to 26% (p <0.01). Thus, pharmacy records indicated that aspirin use was high although it was lower than expected, possibly due to ready availability outside the VAPSHCS pharmacy. The low frequency of beta-blocker use and the increasing reliance on dihydropyridine calcium antagonists through 1995 to treat unstable angina may be an opportunity to improve veteran care according to Agency for Health Care Policy Research recommendations.

Adrenergic beta-Antagonists↗
PubMed1999

Association between percutaneous transluminal coronary angioplasty volumes and outcomes in the Healthcare Cost and Utilization Project 1993-1994.

Studies from a variety of settings have indicated that outcomes for coronary angioplasty are improved when performed in institutions with high caseloads (> 400/year). The purpose of this investigation was to examine the volume outcome hypothesis for coronary angioplasty in a 20% stratified sample of acute care, non-federal hospitals in 17 states. Data were derived from the Nationwide Inpatient Sample from the Health Care Cost and Utilization Project releases 2 and 3. From these records, 163,527 angioplasties from 214 hospitals were selected. Outcomes included hospital mortality, same-admission coronary artery bypass surgery, and a combined end point of either death or same-admission surgery, or both. Hospital volumes were defined as low (< or = 200 cases/year), medium (201 to 400), and high (> 400). Analyses were conducted separately for patients with and without a principal discharge diagnosis of acute myocardial infarction (AMI). For both AMI and no-AMI groups, the rates of adverse outcomes were generally lower in high-volume institutions, and this finding was true in both univariate and multivariate analyses. Although 27% of hospitals were in the low-volume category, only 5% of all procedures were performed in these institutions. Projecting to all United States hospitals for the 2 years, if all procedures performed in low-volume centers had been done in high-volume institutions, 137 deaths could have been averted (90 AMIs, 47 no-AMIs) as well as 404 (46 AMIs, 358 no-AMIs) same-admission surgeries. The results of this study support the hypothesis that better results are obtained in higher volume institutions, but also show that in 1993 and 1994, relatively few patients had their procedures performed in low-volume institutions.

Angioplasty, Balloon, Coronary↗
PubMed1999

Coronary artery stent outcomes in a Medicare population: less emergency bypass surgery and lower mortality rates in patients with stents.

BACKGROUND: Randomized trials of coronary stents versus conventional balloon angioplasty have demonstrated improved short- and long-term outcomes for selected patients receiving stents. The purpose of this study was to compare outcomes in patients receiving stents with those undergoing conventional balloon angioplasty in everyday clinical practice. METHODS AND RESULTS: This study uses information from the Medicare Provider Analysis and Review files for fiscal years 1994 and 1996, the first year the coronary stent code was used. For patients 65 years of age and older, 165,657 cases in 1994 and 201,869 in 1996, including 74,836 cases with stent placement, were identified. Outcomes included hospital deaths, use of same- admission coronary artery bypass surgery, and either or both. Analyses were performed separately for those with and those without a principal diagnosis of acute myocardial infarction. Hospital mortality rates were similar in both years, but the use of same-admission coronary artery bypass surgery was lower in 1996. In that year, for both patients with and those without acute myocardial infarction, hospital death and the use of same-admission coronary artery bypass surgery were lower in the stent group. Additionally, results in the stent group were generally better at high-volume (>200 cases per year) institutions, as was the case for the prestent, 1994 results. CONCLUSIONS: This study documents improved short-term outcomes in older patients who undergo coronary stent placement. Stenting did not eliminate the finding of improved outcomes at high-volume centers.

Aged↗