Basic data related to cardiac testing and cardiac risk associated with vascular surgery

Open repair for ruptured abdominal aortic aneurysm: is it possible to predict survival?

The aim of the study was to determine variables that could be used to predict survival in patients with ruptured abdominal aortic aneurysm (RAAA) and to assess the accuracy of the Glasgow Aneurysm Score (GAS) and the Acute Physiology Chronic Health Evaluation II (APACHE-II). From January 1998 to July 2006, 103 patients underwent operations for RAAA. For each patient, 44 variables were retrospectively recorded in a database. Data were analyzed with univariate and multivariate methods. In the univariate analysis significant predictors of death were hypotension (p=0.001), preexisting peripheral vascular disease (p<0.001), renal insufficiency (p=0.037), chronic obstructive pulmonary disease (p=0.028), level of HCO(3)(-) (p<0.001), intraperitoneal rupture (p=0.001), blood transfused (p<0.001), cardiac complications (p<0.001), and APACHE-II score (p=0.001). Multivariate analysis confirmed statistical significance for coexisting peripheral vascular disease (p<0.001), diastolic blood pressure at admission <60 mm Hg (p=0.039), APACHE-II score >18.5 (p=0.025), HCO(3)(-) <21 mg/dL (p<0.001), and intraperitoneal rupture of the aneurysm (p=0.011) as predictors of death. Results of the study suggested that different factors can be helpful in identifying those patients whose operative risk is prohibitive. APACHE-II, contrary to GAS, is an accurate system to predict postoperative death after repair for RAAA.

Increased urinary albumin excretion rates can be a marker of coexisting coronary artery disease in patients with peripheral arterial disease

Coexisting coronary artery disease (CAD) is an important cause of morbidity and mortality in patients with peripheral arterial disease (PAD). Clinical evaluation and noninvasive tests have some important limitations for the detection of CAD in patients with PAD. The purpose of this study was to investigate whether urinary albumin excretion (UAE) was a sign of atherosclerotic involvement of coronary arteries in patients with PAD. Our study consisted of 65 consecutive patients (56 men, 9 women, mean age; 59.7+/-7.9 years) with PAD who underwent coronary angiography. Urinary albumin excretion was measured in 24-hour urine samples by immunoprecipitation technique. PAD was defined as the presence of > or =50% stenotic lesions in at least 1 of the iliac, femoral, popliteal, tibialis anterior, tibialis posterior, or peroneal arteries. CAD was defined as > or =25% diameter stenosis in at least 1 coronary artery. Patients without any coronary lesions were accepted as having normal coronaries. Age, sex, distributions of coronary risk factors, and UAE rates were compared between patients with and without CAD. Mean UAE was 17.9+/-15.6 mg/day in the total population. Thirty-seven percent of patients had CAD, and 63% had no coronary lesion. UAE rates were 22.33+/-18.74 and 15.32+/-13.01 mg/day in patients with CAD and those with normal coronary arteries, respectively (p = 0.021). Microalbuminuria was detected in 25% in patients with CAD and 12% in those without coronary artery lesions (p = 0.184). The difference was not statistically significant. The distributions of other risk factors and sex were not different between the 2 groups. These data suggest that in patients with PAD, urinary albumin excretion rates may be used to determine those with a high probability of CAD. Further studies are required to decide whether this noninvasive testing is appropriate in detecting high-risk patients.

Surgery for ruptured abdominal aortic aneurysm: early and late results of a prospective study by the AURC in 1989

This study determines the early and late survival rates, the causes of death, and prognostic variables that are associated with early and late survival after for ruptured abdominal aortic aneurysm (AAA). These are based on the prospective analysis of 628 variables of data on 158 consecutive patients in 24 centers of our association in 1989. Patients were followed up for a mean of 42.1 +/- 21.0 months. Six patients were lost to follow-up. To identify the variables that were associated with early and late survival, statistical methods included logistic regression analysis, Kaplan-Meier analysis, and Cox regression analysis. The survival rate was 52.9% +/- 14.4% at 1 month, 48.8% +/- 15.8% at 1 year, 48.1% +/- 16.0 at 2 years, 40.3 +/- 19.2% at 3 years, and 35.0 +/- 21.8 at 4 years. The cause of the 73 (46.2%) early deaths were cardiac (33), hemorrhage (29), colonic necrosis (5), stroke (2), graft infection (2), pneumonia (1), and kidney failure (1). Significant predictors of early death were the presence of a common iliac aneurysm (p < 0.02), the age of the patient (p < 0.02), a previous history of stroke or transient ischemic attack (TIA) (p < 0.04), a bifurcated graft (p < 0.04), a saccular aneurysm (p < 0.06), the blood creatinine level (p < 0.06), and hypotension on admission (p < 0.06). The causes of the 28 (17.7%) late deaths were heart disease (11), cancer (8), stroke (3), another operation (3), graft infection (1), pneumonia (1), and Alzheimer disease (1). Significant predictors of late death were heavy smoking (p < 0.03) and chronic obstructive pulmonary disease (p < 0.07). Rupture of an abdominal aortic aneurysm remains a catastrophic event. Even after a successful cure of a ruptured AAA, cardiovascular causes of death are responsible for survival rates that are significantly lower than that in a matched nonaneurysmal population.

Influence of gender on cardiac risk and survival in patients with infrarenal aortic aneurysms

PURPOSE

To determine whether gender distinction influence the cardiac risk or survival rates associated with surgical treatment of infrarenal abdominal aortic aneurysms (AAAs).

METHODS

From 1983 to 1988, graft replacement of intact AAAs was performed in 490 men (84%) and in 92 women (16%) who had no history of myocardial revascularization before the discovery of their AAAs. Patients of both genders were comparable with respect to mean age (68 years) and the prevalence of coronary artery disease (CAD) by standard clinical criteria (men, 73%; women, 65%). Preoperative coronary angiography was obtained in 471 of the 582 patients (men, 81%; women, 80%) during this particular study period. Preliminary coronary bypass was warranted on the basis of existing indications in 111 (24%) of these 471 patients (men, 25%; women, 18%), including 104 (31%) of the 337 who had clinical indications of CAD (men, 32%; women, 26%) but only 7 (5.2%) of the 134 who did not (men, 6%; women, 4%). Follow-up data were collected during a mean interval of 53 months (men, 54 months; women, 48 months) and were analyzed by Kaplan-Meier survival analysis and Cox proportional hazards models.

RESULTS

Twenty-nine perioperative deaths (5.0%) occurred in conjunction with AAA repair (men, 5.1%; women, 4.3%), and 126 early and late deaths have occurred (men, 22%; women, 22%). Survival rates for the series were found to correlate with age (p < 0.001), the serum creatinine level (p < 0.001), and the coronary angiographic classification (p < 0.001). No significant differences were identified between the gender cohorts. The cardiac mortality rate for AAA resection was only 1.8% in the 111 patients who had preliminary coronary bypass, but five additional perioperative deaths (4.5%) related to renal failure or sepsis occurred in this group. However, 5-year survival rates for patients receiving preliminary bypass (men, 82%; women, 75%) were closely comparable with those for patients found to have only mild to moderate CAD by angiography (men, 86%; women, 82%).

CONCLUSION

We conclude that men and women with AAAs have similar cardiac risks and survival rates associated with surgical treatment. Our results also illustrate that the potential benefit of coronary intervention for severe CAD in patients of either gender must be considered in the context of long-term outcome and the early mortality rate of AAA repair.

Preoperative cardiac risk management

CAD is present in most patients with peripheral arterial disease and is the leading cause of morbidity and mortality after vascular operations. Clinical risk assessment attempts to identify those patients at low, intermediate, or high cardiac risk for adverse cardiac outcomes. Additional tests add little information to the estimates obtained by clinical scoring in patients at low risk. Patients with high cardiac risk scores are clearly at increased risk of experiencing postoperative complications, but further investigations are needed only if knowledge of the functional severity or degree of myocardial ischemia will alter subsequent management. In general, high-risk patients should proceed to coronary angiography, intensive perioperative monitoring, alteration in the planned operation, or avoidance of surgery altogether if indications are less than compelling. Those patients identified as intermediate risk by clinical scoring benefit most from additional tests. In these patients special studies or even coronary arteriography may be useful if the vascular surgery can be delayed until myocardial revascularization is completed. Practically, preoperative cardiac work-up must also consider the indication for surgery. Patients who have threatened limbs or ruptured aneurysms or are severely symptomatic cannot afford the time involved for obtaining additional tests. Moreover, the question of what to do with the information provided by special studies is problematic in these patients. For example, if significant symptomatic or asymptomatic CAD is present in a patient with a gangrenous foot, what is gained by the delay in lower extremity revascularization required when prophylactic CABG is performed? Reports supporting prophylactic CAD intervention are nonrandomized and uncontrolled. CABG and PTCA should be performed only on the merits of the patient's cardiac symptoms and coronary artery anatomy, not to enhance safety of the proposed vascular procedure, because advances in surgical and anesthetic techniques and intraoperative and postoperative monitoring have resulted in lower morbidity and mortality of elective vascular surgery.

Endoluminal aortic aneurysm repair using a balloon-expandable stent-graft device: a progress report

We describe our experience with endoluminal repair of abdominal aortic aneurysms using the stent-graft device. Twenty-four patients underwent 25 procedures in the 27-month period ending December 31, 1992. Twenty-one of the patients were considered high-risk candidates for conventional surgical repair. The endoluminal stented grafts were aortoaortic in 16 procedures and unilateral aortoiliac in eight. One patient underwent a second procedure consisting of an ilioiliac graft to repair a separate common iliac artery aneurysm. Technical problems were primarily related to retrograde transluminal access across the iliac arteries, tortuous aneurysms, and misjudgments as to measurement of length. One patient died and another required secondary deployment of a distal stent at 4 months; subsequent aneurysm expansion mandated surgical replacement at 18 months. It is clear that this device and methodology will have to undergo further refinement before the technique is acceptable for wider clinical application. Current experience, however, is encouraging. Aneurysm exclusion with an endoluminal prosthesis is likely to become an important therapeutic alternative over the next several years.