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The Appropriate Cardiac Evaluation for Peripheral Vascular Disease Patients
Charles O Brantigan, MD 

There is a very high incidence of coronary artery disease (CAD) in patients with peripheral vascular disease (PVD). The mortality rate of PVD patients from CAD is high irrespective of treatment. For years there has been the hope that if the CAD is sought preoperatively through a complete cardiac work-up, then interventions could be made which would minimize subsequent mortality. Unfortunately the morbidity of the cardiac work-up, the morbidity of the subsequent treatment and the relative lack of effectiveness of the treatment have led to the selective application of a "full cardiac work-up" in these patients. The decision making process with limb salvage patients is further complicated because the cardiac work-up delays the attempt to save the limb. That might be justified on the basis of "life over limb," but there is no evidence that the overall mortality of combined cardiovascular and peripheral vascular procedures is less than simply saving the limb (providing that the patients hemodynamics are aggressively managed). Over the past few years surgeons in major referral centers have simply assumed that peripheral vascular disease patients, particularly those considered for limb salvage procedures, all have CAD and have managed them accordingly. Those selected for coronary arteriography are those with ongoing cardiac ischemic symptoms, particularly those who need elective vascular reconstructions. 

Incidence and impact of CAD 

In one of the earliest studies of CAD and PVD, Hertzer of the Cleveland Clinic described the results of coronary arteriography in elective PVD patients1. These patients did not have as severe PVD as we commonly see today. In the first place, many patients whose disease was so severe as to be considered inoperable in 1980 would be considered operable now. In the second place patients with urgent problems or limb salvage as their indication for vascular surgery were excluded. All other patients had coronary arteriograms. The coronary arteries were characterized as normal in 8%, mild to moderately diseased in 32%, severely diseased but compensated in 29%, severely diseased and surgically correctable in 25% and severely diseased and not correctable in 6%. Thus 92% had CAD. For the 25% with severe correctable CAD, coronary artery bypass grafting (CABG) was recommended. The mortality was 5.3%, which should be compared to 1.2% they were reporting for their usual patients at that time. The authors noted that the mortality rate of 5.3% was higher than expected, but in line with the experience of others in operating on high risk patients. Morbidity was not discussed. CABG did make PVD surgery safer. In noting that the combined mortality of CABG plus peripheral reconstruction was the same as for peripheral reconstruction alone, they clearly did not consider the patients who died from CABG, as the mortality for combined procedures was less than the mortality for CABG. Hertzer noted that his recommendations are controversial, but that he recommends coronary arteriography before peripheral vascular reconstruction. In 1989 Hertzer reported the longer-term results of this strategy in discussion of a paper by another author2. This aggressive strategy appeared to work in non-diabetic men on a long-term basis. These patients experienced a 22% mortality or a 6.3% cardiac mortality at 5 years, results comparable to non-PVD patients undergoing CABG. All others (diabetics, women, etc) fared worse, experiencing a 40% mortality or a 23% cardiac mortality in 5 years. 

Peripheral vascular disease is a marker for early mortality in coronary artery disease patients with or without surgical treatment of the CAD. Eagle et al, in a widely quoted study3, reported the results of the Coronary Artery Surgery Study (CASS). 16 249 patients were enrolled in the study between 1974 and 1979 and then randomized into medical and surgical treatment of their CAD. Of this group 2,296 had markers of PVD. At any point in time over the ten-year period, the patient with vascular disease had a 25% increased risk of dying after controlling for all other factors. Cerebrovascular disease, interestingly, was worse with a 43% greater risk of death over time. Peripheral vascular disease was a strong independent predictor of long- term mortality in patients with stable coronary artery disease. They did not give data for PVD with CABG vs. PVD without CABG as they did for the other variables, but it is included in the "all other factors." This is a less severe subset of PVD patients, as they were patients identified with markers for PVD and were not patients proposed for arterial reconstruction. 

The presence of peripheral vascular disease has an adverse impact on the outcome of CAD treatment that is independent of the fact that these patients have more comorbid conditions. Birkmeyer, McDaniel et al in a study of 3003 patients4, compared the short-term results of CABG in patients with and without PVD. Clinical and subclinical indicators of PVD led to a 2.4 fold higher mortality (7.7% compared to 3.2%). Even after adjusting for all comorbidities, PVD patients had a 73% higher chance of dying during a hospitalization for CABG than other patients. Note that this study includes patients with PVD not severe enough to merit intervention and therefore is not exactly applicable to the limb salvage patient. "Controlled studies of the long-term effects of CABG in patients with PVD are needed to determine the optimal role of myocardial revascularization in this population."

Mesh et al (1997)5 noted that CABG was a relatively high risk procedure in PVD patients. They studied a group of 680 patients undergoing CABG. 58 had a standard indication for, or a history of, vascular reconstruction. Limb salvage patients were excluded. Vascular patients experienced a 5.2% mortality from the CABG while those without clinical PVD had only a 2.3% mortality (p=.09). Major morbidity was 3.6 fold higher in patients with PVD compared with those without. "Such morbidity may preclude or alter the timing of subsequent vascular reconstruction."

PVD has an adverse result on the outcome of coronary balloon angioplasty as well. Sutton-Tyrrell studied the effect of PVD on the long term outcome of patients with CAD undergoing balloon angioplasty6. The 5 year survival of PVD patients was 75.8% compared for 90.2% of those without PVD. If anything, this study underestimated the difference, as the patients with PVD included those not severe enough to undergo PVD surgery. In addition the proportion of PVD patients who are candidates for balloon angioplasty instead of CABG is low compared to the general population of CAD patients. 

The presence of PVD adversely affects the longer term outcome of CABG. Birkmeyer7, McDaniel et al reported a study of 2871 patients discharged alive after CABG and noted that the 5 year mortality in PVD patients was 20% compared to 8% for the others. Again, these patients did not necessarily have severe enough PVD to merit surgical reconstruction. In their opinion, whether myocardial revascularization successfully reduces long term mortality in patients with PVD is unclear. Those with multilevel vascular disease had especially high mortalities. They gave three possible explanations for their observations: 

  • Peripheral vascular disease is a marker for diffuse coronary disease not as amenable to complete correction. 
  • PVD may be a marker for "virulent atherosclerosis." 
  • PVD patients may have increased mortality due to sequellae of their noncardiac arterial disease, including stroke, mesenteric ischemia and lower extremity complications. 

They concluded that "The presence of clinical or subclinical PVD is important when predicting both short- and long-term outcomes in patients considering coronary artery bypass surgery." 

We can conclude from these and many other studies that most PVD patients have CAD. CAD is the most common cause of death in PVD patients, but these patients are at markedly increased risk for the various interventional strategies designed to treat CAD. These patients do poorly with treatment of their CAD. A consensus has emerged that subjecting all of these patients to coronary angiography is very expensive and not practical. Many other strategies and screening tests have been proposed to select out the patients that would benefit from prophylactic coronary revascularization. 

Testing and Screening Strategies 

Echocardiography had been proposed as a screening strategy to identify patients with a decreased ejection fraction. A decreased ejection fraction is a marker for poor ventricular function, and as such is a marker for poor surgical outcome. It does not measure cardiac function in an ongoing way, however. In addition patients with diastolic dysfunction may have a normal ejection fraction. For these reasons, cardiac tuning in patients in severe congestive heart failure treatment protocols is usually accomplished using invasive monitoring instead because it is more accurate. Braunwald calls this "tailored therapy8."  Echocardiography has been enhanced by administration of dobutamine, an inotropic agent that increases oxygen demand and leads to dysfunction of myocardial wall segments that have compromised blood supply. This dysfunction can then be visualized by echocardiography. Shafritz et al (1997) studied the utility of dobutamine echocardiography in evaluating patients for elective aortic surgery. In 110 patients there was no statistically significant difference in overall mortality or cardiac mortality between the two groups. The patients were managed aggressively during surgery with invasive monitoring. In spite of these data, they recommend screening in all patients scheduled for elective aortic surgery unless they have a negative coronary disease history, normal EKG and no active cardiac symptoms9.

Treadmill stress tests have been proposed as a method of screening for coronary artery disease. While widely used, they are relatively insensitive and non specific. In addition, many patients proposed for vascular surgery can not walk far enough for a successful test or they wouldn't have been proposed for vascular surgery in the first place. Dipyridamole thallium scintigraphy (DTS) has been proposed as a way to compensate for these weaknesses. The heart is scanned after administration of radioactive thallium, which shows the perfusion of the heart. Dipyridamole (persantine) is then given as a vasodilator. If there is a fixed deficit, that area of myocardium is believed to be a scar with little or no perfusion. If redistribution of the isotope is seen after vasodilation, then the myocardium is believed to have an area of inadequate perfusion. This test correlates well with the results of coronary arteriography, but not with whether the coronary artery disease is amenable to surgery. 

Cutler and Leppo10 used persantine thallium scanning on 116 patients scheduled for aortic reconstruction. The management strategy varied during the series. 51 patients had abnormal studies of which 20 underwent coronary angiography. This procedure resulted in 1 death from a ruptured aneurysm and 1 stroke. Six patients underwent CABG of which 1 died of pancreatitis, producing a 16.7% mortality attributable to the CABG alone. All patients who died in the series did so as a result of the screening strategy. Based on these data, they recommended routine screening. 

Schueppert et al (1996)11 studied the value of preoperative cardiac screening with DTS and radionuclide ventriculography (RNV) in vascular patients. RNV provides information roughly equivalent to the ejection fraction determined by echocardiography. "The finding of severe coronary artery disease led to cardiac revascularization in 17 patients who had no prior history of cardiac disease and 13 patients with a history of angina or myocardial infarction. Two deaths and nine major complications were associated with coronary arteriography and cardiac revascularization." Routine screening did not result in substantial benefit. They concluded that screening may have a more important role in patients with less compelling or entirely elective indications for peripheral vascular surgery. 

Kresowick reported the University of Iowa experience with cardiac screening of vascular surgery patients with DTS in 1997. Patients with recent coronary revascularization or unstable angina were excluded. In 1989 and 1990 they screened 394 consecutive candidates for vascular reconstruction with DTS. 169 patients had a reversible deficit. Of these patients 136 underwent coronary angiography. This procedure produced 1 death and 4 arterial complications requiring surgery. 30 of these patients underwent coronary revascularization (CABG/PTCA).. The mortality was 4.5% with 23% major morbidity. The percentage of interventions per coronary angiogram seems small and not particularly cost effective. 36 patients, or 9.1% did not have vascular surgery because they were considered high risk and their proposed procedure was elective. Of the 343 patients undergoing vascular surgery the mortality was 1.7% with a 3.2% incidence of perioperative myocardial infarction. Thus the risk of the prophylactic myocardial revascularization was higher than the mortality of the vascular surgery. Their results led to a more selective screening process. Their selection protocol became based on whether the information would change the management strategy. Screening is most valuable for patients in whom no vascular surgery is an option. In the case of limb threatening ischemia, these patients have the highest cardiac risk, but non surgical therapy for their peripheral vascular problem is not an option. These same patients are not good candidates for coronary revascularization. Considering that these patients can undergo vascular surgery with an acceptable risk, the risks of screening and prophylactic treatment of coronary artery disease outweigh the benefits. 

Massie et al (1996)12 reported the impact of routine screening of 934 vascular patients with DTS prior to surgery. 297 patients had 2 or more segments of redistribution. Of these, 70 patients had coronary angiography. From the remaining 227 patients, 70 were matched to the coronary angiography group according to risk factors. Of the coronary angiography patients 25% underwent revascularization. This resulted in 3 deaths and 2 myocardial infarctions. The survivors and all of the second group underwent peripheral vascular surgery. The incidence of perioperative non fatal myocardial infarction, perioperative fatal myocardial infarction, late non fatal myocardial infarction and late cardiac death was the same in both groups. Thus, not only was there no advantage to intensive screening and coronary revascularization, but there was significant additional morbidity and mortality. They concluded that the risk of extended cardiac evaluation and treatment did not produce any improvement in either the perioperative or long-term survival rate. 

Seeger et al (1994)13 began with the premise that since cardiac complications are a major cause of death and morbidity following aortic reconstruction, that identifying these patients by stress-thallium scanning would allow coronary arteriography and coronary interventions as appropriate, and would lead to decreased mortality for aortic reconstruction. They compared 146 candidates for elective aortic reconstruction who had routine stress thallium scans as a part of their work-up with 172 patients who did not. Of the screened patients, 41% underwent coronary arteriography compared to 14.7% in the unscreened group. There were 11.6% incidence of CABG/PTA compared to 4.1% in the patients not screened. Stress thallium scanning documented the known high incidence of CAD in PVD patients but provided no other benefit There was no difference in the incidence of fatal postoperative myocardial infarction, serious postoperative myocardial events, overall postoperative cardiac complications or long term survival between the groups. It appears that the added morbidity and mortality of the screening/coronary arteriography, revascularization was not considered. They considered the possibility that other screening tests might be of more value and considered ejection fraction, preoperative electrocardiographic monitoring for silent ischemia, treadmill exercise cardiac stress testing and dobutamine echocardiography. All of these tests had the same limitations as did stress thallium testing. All of the screening tests are reasonable good at picking out the patients who will do well with peripheral vascular surgery, but what is really needed is a way to select the patients who will not. They concluded that the risk and expense or routine preoperative cardiac screening and prophylactic cardiac revascularization can not be justified in patients undergoing peripheral vascular surgical procedures. Basically, their recommendations are that testing for CAD needs to be done based on clinical considerations and not for screening. 

Other screening strategies have been proposed and evaluated. Gajraj and Jamieson14 reviewed the role of screening strategies for cardiac disease prior to peripheral revascularization. They concluded that, although CAD accounts for much of the mortality associated with surgery for PVD, routine coronary arteriography and prophylactic myocardial revascularization is not of any practical value. In patients with clinical evidence of CAD, the operative mortality of vascular surgery is nearly 7%, but the operative mortality for CABG is 5-10% in this same group of patients. The combined mortality of the two procedures provides little benefit even in this relatively high risk group of patients. "The authors believe that the following policy is consistent with the data that have been presented. Patients without clinical evidence of CAD may proceed to surgery without further investigation. Patients with a history of CAD that is stable and not severely limiting should be monitored carefully in the perioperative period. Those with severely symptomatic CAD should be assessed by a cardiologist." Peripheral vascular surgery is not an indication for cardiac screening or prophylactic myocardial revascularization. 

D'Angelo et al (1997)15 discussed the role of cardiac evaluation in the patient undergoing aortic reconstruction. They compared patients who had been screened by varying strategies with those who had not. There was no difference in mortality or morbidity. Considering that the overall mortality in his series of aortic reconstructions was 2.7% it would be hard to justify adding an additional similar mortality that would result from preoperative CABG. "Of course, any patient with cardiac symptoms that on their own warrant further investigation should be fully evaluated before elective surgery." 

Mason et al did a decision analysis of various strategies to prevent cardiac morbidity in patients with mild angina or no angina and a positive dipyridamole thallium scan (DTS). Excluded from the study were patients, such as limb salvage patients, with urgent need for vascular surgery. Vascular disease was assumed to be the dominant clinical problem. Patients with severe angina were excluded. Their dominant clinical problem was considered to be cardiac and the cardiac disease was treated first. Mason et al concluded that proceeding directly to vascular surgery would produce the best clinical results because of the additional morbidity risk of the cardiac procedures. They noted that, "The results of this analysis may appear counterintuitive: How can overall outcome not be improved if PTCA and CABG reduced perioperative cardiac risk by one half to two thirds? The answer appears to lie in the observation that the coronary angiography strategy commits the patient to undergo three procedures (coronary angiography, coronary revascularization, and finally vascular surgery), whereas this vascular surgery strategy exposes the patient to just one procedure. In running the gauntlet of three procedures, the patient must face the risk of death, myocardial infarction, and stroke three times, and therefore the cumulative procedural risk outweighs the benefit." They concluded that coronary angiography and myocardial revascularization in patients with symptomatic peripheral vascular disease is associated with morbidity and mortality rates substantially higher than in patients with symptomatic CAD alone. For this reason "full cardiac work-up" should be reserved for patients whose dominant clinical problem is CAD16.

Summary

All vascular surgeons are engaged in a quest to find ways to decrease the morbidity and mortality of vascular reconstructive surgery. Although PVD patients are beset by a wide variety of other diseases including diabetes, renal failure, wounds, infections and the like, their leading source of mortality is coronary artery disease. Many strategies have been proposed for dealing with the associated CAD ranging from submitting all to coronary arteriography, to screening all patients with one test or another, to selectively screening patients based on various criteria, to not screening at all. All of the proposed screening tests succeed in identifying patients who will do well with reconstructive surgery. None are very specific in picking the ones who will not do well. There is question concerning the effectiveness of the various interventional strategies once critical CAD is found. Not only do PVD patients have higher comorbidity than routine CAD patients, but PVD is an independent marker for increased morbidity and mortality for coronary interventions, both on a short and long term basis. In addition, the group of vascular patients with the highest expected cardiac mortality and morbidity are the limb salvage patients. Their vascular operations are not elective and can not be delayed. They have been historically operated on with a mortality rate less than the mortality of CABG providing that they receive good critical care during the perioperative period. If coronary screening has a role in PVD, it is in the elective patient, the patient whose vascular disease is not critical. These are the patients who will have the best short term and long term results from coronary revascularization. The best strategy for managing combined CAD and PVD appears to be based on clinical judgement. Patients whose clinical presentation includes indications for a coronary intervention should be tested and treated for this. Those whose clinical presentation is one of PVD should simply undergo the peripheral reconstruction, using careful monitoring and management that assumes that there is associated coronary disease.

  1. Hertzer, N et al, Coronary artery disease in peripheral vascular patients, Ann Surg (1984) 199:223-233.

  2. Hertzer, N, discussion in Cutler, BS, Leppo, JA, Dipyridamole thallium 201 scintigraphy to detect coronary artery disease before abdominal aortic surgery, J Vasc Surg (1987) 5:91-100. 

  3. Eagle, K, Rihal, CS, Foster, ED et al, Long-term survival in patients with coronary artery disease: Importance of peripheral vascular disease, J Am Coll Cardiol (1994) 23:1091-5. 

  4. Birkmeyer, JD et al, The effect of peripheral vascular disease on in-hospital mortality rates with coronary artery bypass surgery. Northern New England Cardiovascular Disease Study Group. J Vasc Surg (1995) 21:445-52. 

  5. Mesh, CL et al, Coronary bypass in vascular patients: a relatively high-risk procedure, Ann Vasc Surg (1997) 11:612-9.

  6. Sutton-Tyrrell, K et al, Long term prognostic value of clinically evident non-coronary vascular disease in patients undergoing coronary revascularization in the bypass angioplasty revascularization investigation (BARI), Am J Cardioil (1998) 81:375-81. 

  7. Birkmeyer et al, The effect of peripheral vascular disease on long-term mortality after coronary artery bypass surgery, Northern New England cardiovascular disease study group. Arch Surg (1996) 131:316-21. 

  8. Braunwald, E, Heart Disease, WB Saunders, Philadelphia 1997 p 508. 

  9. Shafritz, R et al, The utility of dobutamine echocardiography in preoperative evaluation for elective aortic surgery, Am J Surg (1997) 174:121-5. 

  10. Cutler, BS and Leppo, JA, Dipyridamole thallium 201 scintigraphy to detect coronary artery disease before abdominal aortic surgery, J Vasc Surg (1987) 5:91- 100. 

  11. Schueppert, MT et al, Selection of patients for cardiac evaluation before peripheral vascular operations, J Vasc Surg (1996) 23:802-9. 

  12. Massie, MT et al, Is coronary angiography necessary for vascular surgery patents who have positive results of dipyridamole thallium scans< J Vasc Surg (1997) 25:975-83. 

  13. Seeger, JM et al, Does routine stress-thallium cardiac scanning reduce postoperative cardiac complications, Ann Surg (1994) 219:654-663. 

  14. Gajraj, H et al, Coronary artery disease in patients with peripheral vascular disease, Brit J Surg (1994) 81:333-342. 

  15. D'Angelo, AJ, et al, Is preoperative cardiac evaluation for abdominal aortic aneurysm repair necessary?. J Vasc Surg (1997) 25:152-6. 

  16. Mason, JJ, Owens, DK, Harris, RA et al, The role of coronary angiography and coronary revascularization before noncardiac vascular surgery, JAMA (1995) 273:1919-1925.

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2003-2004 Dr. Charles Brantigan,  Vascular Surgery Practice
2253 Downing Street, Denver, CO 80205
303.830.8822 fax: 303.830.7068 or 800.992.4676  inquiries@drbrantigan.com

Last Updated: 07/15/2004