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William C Mackey

Publications and source records attributed to William C Mackey.

5 recordsLinked to original sources
PubMed2006

Perioperative myocardial ischemic injury in high-risk vascular surgery patients: incidence and clinical significance in a prospective clinical trial.

OBJECTIVE: The purpose of this study was to assess prospectively the incidence, health care resource utilization, and economic burden associated with perioperative myocardial ischemic injury (PMII) in high-risk patients undergoing noncardiac vascular surgery. METHODS: Two hundred thirty-six patients consented to participate in a pharmacoeconomic substudy as part of a randomized, multicenter clinical trial. Patients were assessed for myocardial ischemic injury by using clinical, biochemical, and electrocardiographic criteria. PMII was defined as fatal or nonfatal myocardial infarction, new or worsened congestive heart failure, or new arrhythmias. Resource utilization parameters were compared for patients with and without PMII. Patients underwent the following index procedures: open abdominal aortic aneurysm repair (n = 44), bypass for aortoiliac disease (n = 29), bypass for femoropopliteal disease (n = 62), bypass for femorotibial disease (n = 71), extra-anatomic bypass (n = 23), and miscellaneous (n = 7). Patients undergoing carotid endarterectomy or only endovascular interventions were excluded. The incremental cost of PMII was estimated by applying the average costs (adjusted to 2004 US dollars) of the hospital ward (dollar 700.00/d) or intensive care unit (dollar 2500.00/d) to the length of stay differences for patients with and without PMII. RESULTS: The overall mortality was 3.4% (8/236), and 7 of 8 deaths were related to PMII. PMII occurred in 42 (17.8%) of 236 patients: 22 myocardial infarctions, 11 congestive heart failures, and 12 new arrhythmias (3 patients had 2 PMII events). There was no evidence of differences in the incidence of PMII among the various index procedures. PMII was associated with a dramatic increase in resource utilization. The mean length of stay was 16.8 and 10.0 days for patients with and without PMII, respectively (P < .001). Intensive care unit care was required by 35 (83.3%) of 42 patients with and 121 (62.4%) of 194 patients without PMII (P < .009). The mean intensive care unit length of stay was 6.6 and 3.7 days for patients with and without PMII, respectively (P < .009). Ten (23.8%) of 42 patients with and 20 (10.3%) of 194 patients without PMII returned to the emergency department for care after discharge (P < .02). CONCLUSIONS: In modern vascular surgery practice, PMII remains common despite the availability of beta-blockers and other preventative strategies. PMII is associated with dramatic increases in resource utilization and cost. The increase in resource utilization associated with PMII resulted in an estimated incremental cost per patient of dollar 9980.00. If 250,000 high-risk open vascular operations are performed annually in the United States, the economic burden of PMII in these procedures alone approximates dollar 444 million. Strategies to decrease PMII incidence and severity should be evaluated in large-scale prospective trials.

Aged↗
PubMed2005

Efficacy of zoniporide, an Na/H exchange ion inhibitor, for reducing perioperative cardiovascular events in vascular surgery patients.

OBJECTIVES: To determine whether a novel Na+/H+ exchange ion inhibitor, zoniporide, is associated with reduced perioperative myocardial ischemic injury in high-risk surgery patients. DESIGN: Randomized double-blind placebo-controlled multidose trial. SETTING: Multicenter worldwide (105 centers) trial. PARTICIPANTS: Patients with known or multiple risk factors for coronary artery disease undergoing noncardiac vascular surgery. INTERVENTIONS: Four parallel groups received 1 of 3 doses of zoniporide or placebo, delivered as a 60-minute loading dose immediately before surgery, and followed by a continuous intravenous infusion for up to 7 days. MEASUREMENTS AND MAIN RESULTS: A total of 824 subjects were randomized into the study from 105 centers worldwide. Of these, 784 subjects received study drug infusion in the 3-mg/kg/d, 6-mg/kg/d, and 12-mg/kg/d groups and the placebo group, and 769 satisfied the criteria for the primary efficacy analysis population. This is 68% of the planned sample size of 1125 subjects. Anesthetic management and perioperative cardiac medications were at the discretion of the attending anesthesiologists, surgeons, and cardiologists. The proportion of subjects who experienced the composite endpoint event (death, myocardial infarction, congestive heart failure, arrhythmia) by postsurgical day 30 was 18.5% in the 12-mg/kg/d group, compared with 15.7% in the placebo group, resulting in a relative risk (RR) of 1.17% (95% confidence interval [CI], 0.80-1.72; p = NS) favoring placebo. The proportions in the lower 2 zoniporide dose groups were slightly lower than in the placebo group, although the sample size is inadequate to reach any firm conclusions. CONCLUSIONS: The results fail to demonstrate the efficacy of zoniporide in reducing the proportion of patients at high risk undergoing noncardiac vascular surgery who experience a composite cardiovascular endpoint, which led the corporate sponsor to stop enrollment early on the basis of a futility analysis of the chance of demonstrating efficacy with a larger sample size.

Adult↗
PubMed2004

Correlation of duplex ultrasound scanning-derived valve closure time and clinical classification in patients with small saphenous vein reflux: Is lesser saphenous vein truly lesser?

OBJECTIVE: We recently identified small saphenous vein (SSV) reflux as a significant risk factor for ulcer recurrence in patients with severe chronic venous insufficiency (CVI) undergoing perforator vein ligation. In this study we examined the role of SSV reflux in patients across the spectrum of CVI. METHODS: From March 15, 1997, to December 24, 2002, clinical and duplex ultrasound (US) scanning data from all valve closure time studies performed in our vascular laboratory were prospectively recorded. Valve closure time in the deep and superficial leg veins was assessed with the rapid cuff deflation technique; reflux time greater than 0.5 seconds was considered abnormal. SSV reflux was correlated with the CEAP classification system and eventual surgical procedure. Data were analyzed with Pearson chi(2) analysis. RESULTS: We analyzed 722 limbs in 422 patients, 265 (63%) female patients and 157 (37%) male patients, with a mean age of 48 +/- 12.8 years (range, 16-85 years). In the entire cohort the cause was congenital (Ec) in 5 patients, primary (Ep) in 606 patients, and secondary (Es) in 112 patients. SSV reflux was present in 206 limbs (28.5%) evaluated. Among limbs with SSV reflux, Ec = 4 (2%), Ep = 162 (79%), and Es = 40 (19%). SSV reflux did not correlate with gender, side, or age. The prevalence of SSV reflux increases with increasing severity of clinical class: C1-C3, 25.8% versus C4-C6, 36.1% (P =.006). SSV reflux is highly associated with deep venous reflux, 35.2% of femoral vein reflux (P =.015), 35.8% of femoral vein plus popliteal vein reflux (P =.001), and 40.5% of isolated popliteal vein reflux (P <.001). Great saphenous vein (GSV) reflux was identified in 483 (67%) limbs studied with valve closure time, whereas SSV reflux was present in 206 (28%) limbs. In this cohort, 127 GSV or SSV surgical procedures were performed subsequent to valve closure time examination. Among these operations 107 (84%) were GSV procedures, and only 20 (16%) were SSV procedures. CONCLUSION: SSV reflux is most common in patients demonstrating severe sequelae of CVI, such as lipodermatosclerosis or ulceration. The increasing prevalence of SSV reflux in more severe clinical classes and the strong association of SSV reflux and deep venous reflux suggest that SSV may have a significant role in CVI. Our data further show that, in our institution, a GSV with reflux is more than twice as likely to be surgically corrected as an SSV with reflux. It is time for the SSV to assume greater importance in the treatment of lower extremity venous disease. Future improvements in surgical techniques for access and visualization of the SSV may facilitate this method.

Cohort Studies↗