Sumita D. Paul

Comparative early and late cardiac morbidity among patients requiring different vascular surgery procedures

PURPOSE The evaluation of coronary artery disease (CAD) in patients undergoing vascular surgery can provide information with respect to perioperative and long-term risk for CAD-related events. However, the extent to which the required surgical procedure itself imparts additional risk beyond that dictated by the presence of CAD determinants remains in question. The purpose of this study was to quantify the relative contributions of specific vascular procedures and CAD markers on perioperative and long-term cardiac risk. METHODS The study cohort comprised 547 patients undergoing vascular surgery from two medical centers who underwent clinical evaluation, dipyridamole thallium testing, and either aortic (n = 321), infrainguinal (n = 177), or carotid (n = 49) vascular surgery between 1984 and 1991. Perioperative and late cardiac risk of fatal or nonfatal myocardial infarction (MI) was compared for the three procedures before and after adjustment for the influence of comorbid factors. These adjusted estimates may be regarded as the component of risk because of type of surgery. RESULTS Perioperative MI occurred in 6% of patients undergoing aortic and carotid artery surgery, and in 13% of patients undergoing infrainguinal procedures (p = 0.019). Significant (p < 0.05) predictors of MI were history of angina, fixed and reversible dipyridamole thallium defects, and ischemic ST depression during testing. Although patients undergoing infrainguinal procedures exhibited more than twice the risk for perioperative MI compared with patients undergoing aortic surgery (relative risk: 2.4[1.2 to 4.5, p = 0.008]), this value was reduced to insignificant levels (1.6[0.8 to 3.2, p = 0.189]) after adjustment for comorbid factors. There was little change in comparative risk between carotid artery and aortic procedures before (1.0[0.3 to 3.6, p = 0.95]) or after (0.6[0.2 to 2.3, p = 0.4]) covariate adjustment. The 4-year cumulative event-free survival rate was 90% +/- 2% for aortic, 74% +/- 5% for infrainguinal, and 78% +/- 7% for carotid artery procedures (p = 0.0001). Predictors of late MI included history of angina, congestive heart failure, diabetes, fixed dipyridamole thallium defects, and perioperative MI. Patients undergoing infrainguinal procedures exhibited a threefold greater risk for late events compared with patients undergoing aortic procedures (relative risk: 3.0[1.8 to 5.1, p = 0.005]), but this value was reduced to 1.3(0.8 to 2.3, p = 0.32) after adjustment. Long-term risk among patients undergoing carotid artery surgery was less dramatically altered by risk factor adjustment. CONCLUSION In current practice, among patients referred for dipyridamole testing before operation, observed differences in cardiac risk of vascular surgery procedures may be primarily attributable to readily identifiable CAD risk factors rather than to the specific type of vascular surgery. Thus the cardiac and diabetic status of patients should be given careful consideration whenever possible, regardless of surgical procedure to be performed.

Geriatric patients with acute myocardial infarction: Cardiac risk factor profiles, presentation, thrombolysis, coronary interventions, and prognosis

Elderly patients have a higher mortality after acute myocardial infarction (MI) yet are treated less aggressively than younger patients. To determine (l) the risk-factor profiles, (2) presentation, (3) management, and (4) hospital outcomes for the elderly (> or = 75 years) compared with middle aged (66 to 74 years) and younger (< or = 65 years) patients in the 1990s, we studied 561 consecutive patients with acute MI. Compared with younger patients, the elderly more frequently had congestive heart failure (40 percent vs 14 percent; p < 0.00001) and non-Q wave infarctions (76 percent vs 56 percent; p < 0.005), received thrombolysis (9 percent vs 34 percent; p < 0.0001), and underwent catheterization (35 percent vs 73 percent; p < 0.00001), percutaneous transluminal coronary angioplasty (9 percent vs 31 percent; p < 0.0002), and coronary artery bypass grafting (5 percent vs 15 percent; p < 0.03) less frequently. Those who did not receive thrombolysis all had contraindications. Mortality was higher in the elderly (19 percent vs 5 percent; p < 0.004), especially among those who did not receive thrombolysis (20 percent vs 7 percent; p < 0.03). Multivariate predictors of mortality included age, and congestive heart failure. In addition, when clinical course and management variables were considered, use of the intraaortic balloon pump was a predictor of mortality, whereas undergoing coronary angiography was a negative predictor (relative risk, 0.3; 95 percent confidence intervals, 0.1 to 0.6).

Do gender-based differences in presentation and management influence predictors of hospitalization costs and length of stay after an acute myocardial infarction?

Previous studies have reported conflicting results on gender differences in the management of acute myocardial infarction (AMI) and have not evaluated hospital length of stay or costs. To determine gender-based differences in presentation, management, length of stay, costs, and prognosis after AMI, we studied 561 patients with AMI. Women were older, had systemic hypertension, diabetes mellitus, and a non-Q-wave AMI more frequently, whereas more men smoked cigarettes. Predictors of coronary angiography were: male gender (RR 1.9; 95% CI 1.2 to 3.1), chest pain at presentation (RR 1.8; 95% CI 1.0 to 3.3), recurrent angina (RR 4.1; 95% CI 2.5 to 6.8), admission via the emergency room (RR 0.2; 95% CI 0.1 to 0.3), and younger age. Gender did not predict mortality. Among presenting features, the predictors of length of stay were diabetes, prior coronary bypass and prior coronary angioplasty in men, and age alone in women. Pulmonary edema and need for coronary bypass during the hospital course were predictors of length of stay in men only. Among presenting features, predictors of cost were diabetes in men and congestive heart failure in women. Predictors of cost during hospitalization for men were pulmonary edema, coronary angiography, intraaortic balloon pump use, and coronary bypass; for women, they were peak levels of creatine kinase and coronary bypass. Thus, predictors of length of stay and hospitalization costs differ based on gender. Efforts at cost containment may need to be gender-specific.

Sex Differences in Perioperative and Long-term Cardiac Event–Free Survival in Vascular Surgery Patients An Analysis of Clinical and Scintigraphic Variables

BACKGROUND Little information is available regarding the occurrence of perioperative and late cardiac events in women with vascular disease. The current study was performed to examine whether sex-specific differences exist in these outcomes in a large population of vascular surgery patients and to determine the value of clinical and dipyridamole thallium variables in predicting myocardial infarction and cardiac death. METHODS AND RESULTS Preoperative dipyridamole thallium imaging was performed in 567 vascular surgery patients, including 380 men and 187 women. The incidence of nonfatal myocardial infarction and cardiac death was noted during the perioperative period and during a follow-up period of 50 +/- 5 months. Fixed and reversible thallium perfusion abnormalities were more common in men than in women (P < .001 and P = .004, respectively). Perioperative cardiac event rates were similar in men and women, 8.4% and 7.5%, respectively (P = .07). A transient thallium defect was associated with an increased risk of cardiac events by 3.9-fold in men (CI, 1.5 to 10.2) and 5.5-fold in women (CI, 1.4 to 22). Various clinical factors also were predictive of events but demonstrated substantial sex differences. For example, dipyridamole-induced ST-segment depression was strongly associated with perioperative events in men but not in women. There were 22 nonfatal myocardial infarctions and 29 cardiac deaths in men during the follow-up period, with comparable event rates noted for women. Cardiac event-free survival rates also were similar for men and women (P = .40). Multivariate analysis demonstrated that a history of heart failure was an important prognostic variable for both sexes, as was a fixed thallium defect. Significant sex differences in the predictive value of other clinical factors for late cardiac events was apparent. CONCLUSIONS The present study demonstrates that (1) thallium perfusion defects are more common in men; (2) transient thallium defects are associated with perioperative myocardial infarction and cardiac death in both sexes; (3) long-term survival rates after vascular surgery are similar between men and women; (4) a fixed perfusion defect is predictive of late cardiac events in women, with a trend noted in men; and (5) sex-specific differences were noted with regard to the prognostic value of various clinical risk factors. Therefore, dipyridamole thallium plays a significant role in the assessment of perioperative and long-term prognosis for both male and female vascular surgery patients. On the basis of these observations, modifications in risk stratification based on sex may be appropriate for men and women with vascular disease.

Impact of a Simple Inexpensive Quality Assurance Effort on Physician's Choice of Thrombolytic Agents and Door-to-Needle Time: Implication for Costs of Management

The objective of this study were to assess the impact of a quality assurance effort on the door-to-needle time and the choice of thrombolytic agent for the management of acute myocardial infarction in the emergency department. The study design involved a prospective collection of data on a series of consecutive patients who received a thrombolytic agent for a presumed acute myocardial infarction. The study was carried out in the emergency department of a major university urban tertiary care center. A total of 349 patients were studied from September 1989 to March 1994. The quality assurance program began in 1989 and included chart review of all patients receiving thrombolytic therapy, with special attention to all patients with door-to-needle times >60 minutes to identify causes for delay. Feedback was directed to pharmacy, nursing, and physician staff. Biannual reports were distributed throughout the hospital and the emergency department. Nursing-specific feedback led to the development of protocols for all aspects of the delivery of thrombolytic agents. The choice of thrombolytic agent was not dictated by the protocol, but the physician staff was continuously updated on the results of the latest clinical trials comparing one thrombolytic agent with another. The mean age was 58 years for men and 67 years for women in this cohort consisting of 78% men and 22% women. Thirty-seven percent of the myocardial infarctions were in an anterior location and 56% were in an inferior location. The median duration of chest pain before presentation to the emergency department was 120 minutes. Hospital mortality was 3%. Median door-to-needle time fell from 46 (1989–1991) to 36 (1992–1994) minutes, P < 0.01. The percentage of patients with a door-to-needle time >60 minutes decreased from 35% (1989–1991) to 16% (1992–1994) minutes, P < 0.0001. Corresponding with the ISIS-3 report, there was a significant increase in the proportion of patients receiving streptokinase over the first 3 years of the study (P < 0.0001), which changed to a trend toward increased utilization of tissue plasminogen activator with the GUSTO report in the final 6 months of the study. In conclusion, a quality assurance program led to a significant reduction in the door-to-needle time, and recent megatrials were found to influence the choice of thrombolytic agent used.

A stepwise strategy for coronary risk assessment for noncardiac surgery

Physicians should adapt a systematic approach to cardiac risk stratification for patients being considered for noncardiac surgery, involving clinical evaluation, functional assessment, and surgical risk assessment for all patients and then deciding which patient needs to undergo noninvasive testing, coronary angiography and revascularization, perioperative monitoring, and aggressive postoperative care.

Use of exercise test parameters to predict presence and duration of ambulatory ischemia in patients with coronary artery disease.

Myocardial ischemia is an indicator of adverse prognosis. In patients with stable angina and positive exercise tests, prolonged cumulative ischemia on ambulatory electrocardiographic monitoring identifies a high-risk group with severe coronary artery disease and poor survival. To determine whether features of the exercise test can accurately (1) predict the occurrence of ambulatory ischemia, and (2) classify patients into subgroups at varying levels of risk for ambulatory ischemia, we studied 48 patients with a history of angina and documented coronary disease who underwent the standard Bruce protocol and ambulatory monitoring. All patients had a positive exercise treadmill test, and 26 had ischemia on Holter monitoring (total of 2,922 minutes, 173 episodes, 94% with silent ischemia). The remaining 22 patients did not have ischemia. The exercise test parameters showing significant differences between the 2 groups were (1) time to > or = 1 mm ST-segment depression (p < 0.0003), (2) maximal ST-segment depression (p < 0.004), and (3) exercise capacity (p < 0.037). These data were used to develop a model for predicting the presence and the severity of ambulatory ischemia. Time to onset of > or = 1 mm ST-segment depression and maximal ST-segment depression on exercise treadmill testing can be used to determine the likelihood of mild (1 to 5 episodes or lasting < or = 60 minutes) or severe prolonged (> 5 episodes or lasting > 60 minutes) ambulatory ischemia. Patients with a very high or very low probability of ischemia on Holter monitoring can be identified by certain exercise test parameters and may not need to undergo monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)