Biomedical subjects

David O Williams

Publications and source records attributed to David O Williams.

41 records · Page 3Linked to original sources

PubMed2002

Comparison of patients undergoing enhanced external counterpulsation and percutaneous coronary intervention for stable angina pectoris.

Enhanced external counterpulsation (EECP) has recently emerged as a treatment option for angina in selected patients suitable for revascularization with percutaneous coronary intervention (PCI). We compared baseline characteristics and 1-year outcome in 2 cohorts of PCI candidates presenting with stable symptoms: 323 patients treated with EECP in the International EECP Patient Registry (IEPR), and 448 NHLBI Dynamic Registry patients treated with elective PCI. Compared with patients receiving PCI, IEPR patients had a higher prevalence of many risk factors including prior PCI (53.0% vs 33.3%, p <0.001), prior coronary artery bypass grafting (42.1% vs 18.6%, p <0.001), prior myocardial infarction (56.4% vs 27.8%, p <0.001), history of congestive heart failure (16.8% vs 9.2%, p <0.01), and history of diabetes (37.9% vs 23.5%, p <0.001). Left ventricular ejection fraction was lower among IEPR patients (mean 50.3% vs 59.2%, p <0.001). At 1 year, survival was comparable in the 2 cohorts (98.7% IEPR vs 96.8% PCI, p = NS), as were rates of coronary artery bypass grafting during follow-up (4.5% IEPR vs 5.7% PCI, p = NS). At 1 year, 43.7% of IEPR patients reported no anginal symptoms compared with 73.4% of Dynamic Registry patients (p <0.001). Rates of severe symptoms (Canadian Cardiovascular Society class III, IV, or unstable) at 1 year were 15.5% among IEPR patients and 9.5% in the Dynamic Registry (p = 0.02). PCI candidates suitable for and treated with EECP had 1-year major event rates comparable to patients receiving elective PCI. Although PCI was associated with substantially lower rates of 1-year symptoms, EECP may be a safe treatment option for selected patients with obstructive coronary disease.

Age Factors↗

PubMed2002

Improved outcomes for women undergoing contemporary percutaneous coronary intervention: a report from the National Heart, Lung, and Blood Institute Dynamic registry.

OBJECTIVES: The goal of this study was to determine whether women undergoing contemporary percutaneous coronary intervention (PCI) remain at increased risk in comparison with men and whether the outcomes in women have improved. BACKGROUND: Previous studies have shown that women treated with coronary angioplasty have a higher incidence of procedural morbidity and mortality than men. METHODS: Gender differences in wave 1 of the National Heart, Lung and Blood Institute (NHLBI) Dynamic registry were evaluated. Baseline characteristics and outcomes in women in the Dynamic registry were compared with those in women in the 1985-1986 and 1993-1994 NHLBI Percutaneous Transluminal Coronary Angioplasty (PTCA) registries. RESULTS: Women were older with a higher prevalence of diabetes mellitus, hypertension, congestive heart failure, unstable angina and single vessel disease in comparison with men. Although procedural success and in-hospital death (2.2% vs. 1.3%), myocardial infarction (MI) (2.3% vs. 3.0%) and coronary artery bypass graft surgery (CABG) (1.3% vs. 1.4%) were similar in women and men, respectively, one-year mortality (6.5% vs. 4.3%, p = 0.02) and combined end point of death/MI/CABG (18.3% vs. 14.4%, p = 0.03) were higher in women than in men. After controlling for other factors, gender was not a significant predictor of death or death plus MI at one year. Despite a higher risk profile in women in the Dynamic registry in comparison with women in the 1985-1986 NHLBI PTCA registry, in-hospital death/MI/CABG was lower (6.0% vs. 11.6%, p < 0.001). CONCLUSIONS: Despite persistent high-risk characteristics in women, gender differences in outcomes in patients undergoing contemporary PCI have decreased, and outcomes in women have improved.

Aged↗

PubMed2002

Thrombolytic therapy vs primary percutaneous coronary intervention for myocardial infarction in patients presenting to hospitals without on-site cardiac surgery: a randomized controlled trial.

CONTEXT: Trials comparing primary percutaneous coronary intervention (PCI) and thrombolytic therapy for treatment of acute myocardial infarction (MI) suggest primary PCI is the superior therapy, although they differ with respect to the durability of benefit. Because PCI is often limited to hospitals that have on-site cardiac surgery programs, most acute MI patients do not have access to this therapy. OBJECTIVE: To determine whether treatment of acute MI with primary PCI is superior to thrombolytic therapy at hospitals without on-site cardiac surgery and, if so, whether superiority is durable. DESIGN: The Atlantic Cardiovascular Patient Outcomes Research Team (C-PORT) trial, a prospective, randomized trial conducted from July 1996 through December 1999. SETTING: Eleven community hospitals in Massachusetts and Maryland without on-site cardiac surgery or extant PCI programs. PATIENTS: Four hundred fifty-one thrombolytic-eligible patients with acute MI of less than 12 hours' duration associated with ST-segment elevation on electrocardiogram. INTERVENTIONS: After a formal primary PCI development program was completed at all sites, patients were randomly assigned to receive primary PCI (n = 225) or accelerated tissue plasminogen activator (bolus dose of 15 mg and an infusion of 0.75 mg/kg for 30 minutes followed by 0.5 mg/kg for 60 minutes; n = 226). After initiation of assigned treatment, all care was determined by treating physicians. MAIN OUTCOME MEASURES: Six-month composite incidence of death, recurrent MI, and stroke; median hospital length of stay. RESULTS: The incidence of the composite end point was reduced in the primary PCI group at 6 weeks (10.7% vs 17.7%; P =.03) and 6 months (12.4% vs 19.9%; P =.03) after index MI. Six-month rates for individual outcomes were 6.2% vs 7.1% for death (P =.72), 5.3% vs 10.6% for recurrent MI (P =.04), and 2.2% vs 4.0% for stroke (P =.28) for primary PCI vs thrombolytic therapy, respectively. Median length of stay was also reduced in the primary PCI group (4.5 vs 6.0 days; P =.02). CONCLUSIONS: Compared with thrombolytic therapy, treatment of patients with primary PCI at hospitals without on-site cardiac surgery is associated with better clinical outcomes for 6 months after index MI and a shorter hospital stay.

Angioplasty, Balloon, Coronary↗

PubMed2002

Angina 1 year after percutaneous coronary intervention: a report from the NHLBI Dynamic Registry.

BACKGROUND: As percutaneous coronary intervention (PCI) is most commonly performed for relief of angina, it is important to identify factors associated with recurrence of anginal symptoms. METHODS: We examined symptoms at 1-year follow-up in 1755 consecutive NHLBI Dynamic Registry patients who underwent PCI in the setting of symptoms or acute infarction. RESULTS: At 1-year follow-up, 26% of patients reported angina in the previous 6 weeks. Younger patients and females reported more symptoms. History of coronary artery bypass graft (CABG) or PCI, prior myocardial infarction (MI), diabetes, graft disease, and extensive coronary artery disease (CAD) (>4 significant lesions) were also associated with follow-up angina. Patients receiving stents reported less angina (24% vs 29%, P <.05). Completely revascularized patients and those with residual single-vessel disease had comparable 1-year angina rates (23% both subgroups), while 32% of patients with residual multivessel CAD reported symptoms. Patients undergoing repeat PCI during follow-up reported more 1-year angina than others (34% vs 24%, P <.001), whereas those undergoing CABG after post-PCI hospitalization had less symptoms (15% vs 26%, P <.05). After adjustment for baseline symptom status and outcome of index PCI, residual CAD, and reintervention during follow-up, patient characteristics significantly predictive of angina included female sex, age <62 years, and prior MI. CONCLUSIONS: While approximately three quarters of patients receiving PCI are angina-free at 1 year, females continue to have more symptoms, as do other subgroups including patients with history of MI or previous intervention. As these symptoms are associated with self-reported activity and quality of life limitation, evaluations of PCI should include angina as a key follow-up outcome.

Age Factors↗

PubMed2002

Effect of endomyocardial laser channels on regional innervation shown with (125)I-MIBG and autoradiography.

UNLABELLED: The aim of this study was to map regional innervation against regional flow early after laser channel placement using autoradiography in a porcine model. METHODS: Four juvenile male swine underwent left ventricular mapping using a catheter-based mapping system and laser treatment with 20-30 channels to the mid and distal anterior wall of the left ventricle. Three days later animals were injected with 37 MBq (125)I-metaiodobenzylguanidine (MIBG) followed in 3 h with 1,110 MBq (99m)Tc-sestamibi; 1 h later the animals were killed. Hearts were removed, perfusion fixed, and sliced into 1-cm slices. The slices best showing laser holes were selected, and circumferential sections were taken for autoradiography and hematoxylin-eosin staining. Phosphor screens were exposed for (99m)Tc and (125)I, and images were processed. The MIBG image was subtracted from the methoxyisobutylisonitrile (MIBI) image and vice versa, and color tables were applied to the difference images and overlaid on the perfusion images. Quantitative analysis of the light image data was also performed. RESULTS: Thirty-three sections from the last 3 experiments were analyzed. Acoustic damage from 30 laser channels was identified from the hematoxylin-eosin sections. Reduced MIBG relative to regional flow was seen in surrounding tissue corresponding to only 1 channel. There was no statistically significant difference in light units expressed as (MIBG - MIBI)/maximal MIBG value between laser channels and unmarked myocardial map regions. The regions identified from the color table on the map as low MIBG relative to MIBI were significantly lower than remaining laser channels and remaining myocardium. Mean light units for the regions with high MIBG relative to MIBI were significantly higher than the remaining laser channels and remaining myocardium. CONCLUSION: Using a high-resolution technique correlated with microscopic pathology in an animal model, there is negligible regional denervation 3 d after placement of endomyocardial laser channels.

3-Iodobenzylguanidine↗