Preoperative Cardiac Testing Research Articles

Functional outcome after surgical treatment for intermittent claudication

Although patency data for lower extremity bypass grafts are readily available, few reports have focused on patients' satisfaction after surgical reconstruction for claudication. We reviewed our experience with surgical treatment for claudication, focusing on late outcome from the patients' perspective to further refine surgical decision making in patients with intermittent claudication. From February 1987 through April 1994, 114 consecutive patients underwent surgical bypass for intermittent claudication. Nine patients were lost to follow-up, leaving the study cohort composed of 105 patients with a mean age of 63 years (range 42 to 82 years). Sixty-two percent of the procedures were inflow reconstructions, and the remainder were infrainguinal bypasses. Clinical and demographic data were gathered from record review, and late follow-up was obtained by return visit or telephone interview. Patient satisfaction and level of function were assessed by a simple five-point questionnaire administered by a research nurse. Actuarial methods were used to calculate late graft patency and survival. Cox regression analysis was used to identify clinical and anatomic factors predictive of late survival and favorable outcome. Cardiac risk assessment revealed that 75% of patients either had no clinical markers for cardiac disease or had been treated with previous coronary artery bypass grafting or percutaneous transluminal angioplasty; despite this 61% of patients underwent specific preoperative cardiac testing. Most (68%) inflow procedures were aortobifemoral bypass grafts, and 93% of outflow procedures were femoropopliteal bypass grafts. Two thirds of infrainguinal grafts were performed with autogenous conduits, with prosthetic femoropopliteal bypass grafts performed only to the above-knee popliteal artery. Early graft failure with successful immediate revision occurred in 5% of patients. No operative deaths or early or late amputations occurred. At a mean follow-up of 4.5 years 96% of surviving patients had a patent graft. However, primary unassisted patency at 4 years was superior for inflow (92% +/- 4%) versus outflow (81% +/- 6%) procedures (p = 0.009). Late readmission for cardiac-related events occurred in 12%, and late cardiac-related death occurred in 5%. Actuarial survival at 5 years was 80% +/- 5%, with diabetes being the only negative survival predictor (risk ratio 2.6, 95% confidence interval 1 to 7, p = 0.049); 60% of late deaths were cancer-related. Satisfactory late results were reported by 82% of patients, with age < or = 70 years (odds ratio 4.01, 95% confidence interval 1.2 to 13.7, p = 0.026) and normalization ( > or = 0.85) of ankle/brachial index (odds ratio 5.7, 95% confidence interval 1.6 to 20, p = 0.008) being powerful independent predictors of patient satisfaction. After considering cardiac-related short- and long-term prognosis, we conclude that lower extremity bypass grafting for intermittent claudication will produce optimal results when restricted to younger ( < 70 years) nondiabetic patients in whom near normalization of the postoperative ankle/brachial index can be anticipated.

Postoperative Management Strategies May Obviate the Need for Most Preoperative Cardiac Testing

Postoperative Management Strategies May Obviate the Need for Most Preoperative Cardiac Testing

Effect of anesthetic technique on cardiac morbidity following carotid artery surgery

To investigate the effect of anesthetic technique on cardiac morbidity after carotid artery surgery. From 1991 to 1994, 266 consecutive carotid endarterectomies were performed under local/regional (n=140) or general anesthesia (n=126). The effects of anesthetic technique on postoperative adverse cardiac events were assessed retrospectively. Preoperative cardiac testing was performed in all patients undergoing general or local/regional anesthesia. Medical characteristics were similar among patients in both groups. Forty-seven adverse cardiac events (4 myocardial infarction, 9 congestive heart failure, 7 angina, and 27 new ventricular dysrhythmias) occurred postoperatively in 38 patients (14.3%). There were no deaths. The relative risks of general anesthesia for dysrhythmias, myocardial infarction, angina, congestive heart failure, and total adverse cardiac events were 2.22, 0.37, 0.83, 1.38, and 1.5, respectively. The only statistically significant differential was the increased risk of postoperative dysrhythmias after general anesthesia (P<0.03). Major cardiac morbidity following carotid endarterectomy is independent of anesthetic technique.

Perioperative cardiac morbidity

Over the past 35 yr, approximately 100 outcome studies have examined the problem of PCM in patients undergoing noncardiac surgery. Most have focused on preoperative historical predictors, of which only a recent MI or present CHF are proven predictors of PCM. The efficacy and cost-effectiveness of specialized preoperative cardiac testing, such as exercise stress testing or dipyridamole-thallium imaging, remain controversial. Outcome studies of intraoperative predictors have shown that anaesthetic choice does not affect outcome, but that emergency surgery, major vascular surgery, and prolonged thoracic or upper abdominal surgery are associated with increased risk. Among the dynamic intraoperative risk factors, hypotension and tachycardia appear to predict outcome. Myocardial ischaemia, although potentially important, has not been studied rigorously in patients undergoing noncardiac surgery. Studies of the postoperative period are few. Preliminary data suggest that postoperative risk factors for PCM may be at least as critical as intraoperative factors. There appears to be a high incidence of haemodynamic stresses and of myocardial ischaemia during the postoperative period. However, the relationship of postoperative ischaemia to outcome is, as yet, unknown.

Cardiac risk screening of peripheral arterial surgical patients by the use of combined simple clinical and non-invasive cardiodynamic parameters

Arterial surgical patients have a poor long-term survival and suffer significant risks of experiencing perioperative cardiac events, mainly due to a high incidence of coronary atherosclerosis impairing left ventricular function. The perioperative cardiac risk can be assessed by use of clinical cardiac risk indices, which are inexpensive but may have suboptimal sensitivity, or by more extensive cardiac tests. In this study the efficacy of a combined, non-invasive and inexpensive technique of risk assessment was prospectively evaluated in 195 patients undergoing peripheral arterial surgery (aortic aneurysms not included). All patients were preoperatively examined by a nurse registering the Detsky cardiac risk index score (DRI) and performing resting computerised bioimpedance cardiodynamic measurements (CM). Cardiac deaths (CD, n = 6), potentially lethal cardiac complications (PLC, n = 11) within 30 days and long-term survival during 20 +/- 12 (S.D.) months of follow-up were identified. CD was best predicted by combining CM and DRI, while PLC was best predicted by combining DRI and the haemoglobin concentration of the blood (Hb). A group without CD containing 88% of the cases was identified. Furthermore, the combination of DRI < or = 10 and Hb > 120 g/l identified a low risk group (57% of all cases) with no PLC or CD. Using CM, DRI and Hb in combination, patient groups with long-term survival from 0-90% were identified. We conclude that this inexpensive cardiac risk screening both identifies low risk vascular surgical patients, for whom more sophisticated preoperative cardiac testing can be omitted, and predicts long-term survival.

Coronary artery disease in surgical patients. Preoperative evaluation.

Primary care physicians play a major role in the risk stratification of patients with coronary artery disease (CAD) preparing for noncardiac surgery. Preoperative risk assessment takes into account the type and urgency of surgery and the extent of underlying CAD. With this approach, patients can be categorized as being at high, intermediate, or low risk for postoperative cardiac complications. Judicious use of preoperative noninvasive cardiac testing may help identify those patients at particularly high risk for such complications.

Use of stress thallium imaging to stratify cardiac risk in patients undergoing vascular surgery

Reduction of the cardiac morbidity associated with major vascular procedures requires identification of high risk patients prior to operation. This retrospective study reviews the records of 126 consecutive patients who underwent 141 major vascular procedures to determine the accuracy of preoperative clinical, laboratory (ECG), and cardiac function testing (stress thallium-201 scintigraphy, left ventricular ejection fraction scan) in predicting perioperative cardiac complications. An abnormality on oral dipyridamole or treadmill thallium imaging was demonstrated prior to 71 (61%) of 116 procedures and included 20 fixed and 51 reperfusion (reversible) defects. No patient died within 30 days of operation, but 11 minor (ventricular arrhythmia) and 15 major (myocardial infarction, ischemic congestive heart failure) cardiac complications occurred. A reperfusion defect on stress thallium imaging accurately (94% sensitivity, 56% specificity, 98% negative predictive value) identified high-risk patients while accepted clinical rating systems (Goldman, Cooperman, Eagle) and preoperative level of left ventricular ejection fraction were less predictive of adverse cardiac events. Patients without myocardium at risk by coronary angiography, but a reperfusion defect on stress thallium imaging were found to be at high risk for a cardiac complication. The study data support the use of stress thallium imaging to stratify cardiac risk prior to major arterial surgery.

The impact of selective use of dipyridamole-thallium scans and surgical factors on the current morbidity of aortic surgery

Preoperative cardiac testing in patients undergoing vascular surgery remains controversial. We have advocated selective use of dipyridamole-thallium scans based on clinical markers of coronary artery disease before aortic surgery. The present study assessed both the efficacy of this policy and the role of surgical factors in the current morbidity of aortic reconstruction. Two hundred two elective aortic reconstructions (151 abdominal aortic aneurysms, 51 aortoiliac occlusive disease) performed in the period from January 1989 to June 1990 were reviewed. Preoperative dipyridamole-thallium scanning was performed in 29% of all patients, prompting coronary angiograms in 11% and coronary artery bypass grafting/percutaneous transluminal coronary angioplasty in 9% of patients before aortic reconstruction. The overall operative mortality rate was 2%, with one cardiac-related death. Major cardiac (nonfatal myocardial infarction, unstable angina) and pulmonary complications occurred in an additional 4% and 6%, respectively, of patients. Coronary artery disease clinical markers and surgical factors were analyzed with stepwise logistic regression for the prediction of operative mortality rates and major cardiopulmonary complications. Variables retaining significance in predicting postoperative death or cardiopulmonary complications included prolonged (more than 5-hour) operative time (p < 0.004), operation for aortoiliac occlusive disease (p < 0.010), and a history of ventricular ectopy (p < 0.002). Prolonged operative time (p < 0.006) and the detection of intraoperative myocardial ischemia (p < 0.030) were predictive of major cardiac complications after univariate analysis. Selective use of the dipyridamole-thallium scan based on certain clinical markers of coronary artery disease will identify the approximately 10% of patients undergoing aortic reconstruction in whom preoperative invasive treatment of coronary artery disease is appropriate. Thereafter, the overall morbidity of aortic reconstruction, albeit minimal, is dominated by surgical factors rather than the extent of antecedent coronary artery disease. (J Vasc Surg 1992;15:43–51.)

The impact of selective use of dipyridamole-thallium scans and surgical factors on the current morbidity of aortic surgery

Preoperative cardiac testing in patients undergoing vascular surgery remains controversial. We have advocated selective use of dipyridamole-thallium scans based on clinical markers of coronary artery disease before aortic surgery. The present study assessed both the efficacy of this policy and the role of surgical factors in the current morbidity of aortic reconstruction. Two hundred two elective aortic reconstructions (151 abdominal aortic aneurysms, 51 aortoiliac occlusive disease) performed in the period from January 1989 to June 1990 were reviewed. Preoperative dipyridamole-thallium scanning was performed in 29% of all patients, prompting coronary angiograms in 11% and coronary artery bypass grafting/percutaneous transluminal coronary angioplasty in 9% of patients before aortic reconstruction. The overall operative mortality rate was 2%, with one cardiac-related death. Major cardiac (nonfatal myocardial infarction, unstable angina) and pulmonary complications occurred in an additional 4% and 6%, respectively, of patients. Coronary artery disease clinical markers and surgical factors were analyzed with stepwise logistic regression for the prediction of operative mortality rates and major cardiopulmonary complications. Variables retaining significance in predicting postoperative death or cardiopulmonary complications included prolonged (more than 5-hour) operative time (p less than 0.004), operation for aortoiliac occlusive disease (p less than 0.010), and a history of ventricular ectopy (p less than 0.002). Prolonged operative time (p less than 0.006) and the detection of intraoperative myocardial ischemia (p less than 0.030) were predictive of major cardiac complications after univariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Pre-operative assessment of the patient with cardiac disease

Perioperative cardiac morbidity remains a significant problem throughout the world. Its solution requires identification of the at-risk patient to assess monitoring and therapeutic requirements throughout the perioperative period. Assessment of patients with cardiac disease is particularly challenging for several reasons. First, patients can present with a myriad of symptom complexes with varying degrees of clinical and subclinical ventricular dysfunction. And, secondly, we are in the age of cost-containment. There is increasing pressure on the anaesthesiologist to expedite the preoperative assessment given the rising population of come-and-go and come-and-stay surgery. In addition, the number and kind of preoperative cardiac tests will be limited. Thus, today, more than ever, the anaesthesiologist must have a thorough understanding of the types of preoperative cardiac tests available, the information they provide, and the indications for their use. This chapter represents a source of information regarding the routine and non-routine preoperative tests available to anaesthesiologists, and will hopefully allow rational use of these important preoperative tests.

Postoperative physiopathologic results in mitral stenosis

The physiopathologic results of mitral commissurotomy were studied at intervals of several months, one year, two years, and three years after the operation. Pericarditis occurred after the operation in 90 per cent of the cases; and postpericardiotomy syndrome (the so-called postcommissurotomy syndrome) in 12.5 per cent, with no correlation between this and the results of biopsy of the auricular appendage. The results of mitral commissurotomy were evaluated by preoperative and postoperative cardiac catheterization, phonocardiogram, electrocardiogram, vectorcardiogram, electrokymogram, ballistocardiogram, roentgenogram, pulmonary angiocardiogram, and pulmonary function tests. The physiopathologic data did not always correspond to the clinical results. Sometimes the clinical improvement was greatly superior to the results furnished by these tests. In this series of 200 patients, excellent or good clinical results were obtained in 67 to 70 per cent of the cases. There was a mortality of 6 per cent. Finally, some factors are present which condition the physiopathologic results of mitral commissurotomy: postoperative mitral insufficiency, valvular calcification, postoperative emboli, insufficiency of the myocardium, sub-valvular stenosis, insufficient commissurotomy, and recurrent rheumatic reactivation, which may cause rcstenosis.