Propaedeutical Endovascular Interventions in High-Risk Candidates for Coronary Surgery

Abstract

Purpose. Peripheral vascular disease (PVD) is a major risk factor in candidates for coronary surgery, impacting the overall mortality and morbidity in the preoperative time and follow-up after coronary surgery. High-risk patients with PVD may benefit from endovascular treatment prior to coronary surgery. We sought to identify, in high-risk patients, the most frequent clinical settings requiring propaedeutical endovascular treatment before coronary surgery, the results, and the mid-term impact on subsequent surgical revascularization. Methods. Between November 2002 and November 2004, 16 high-risk patients (9 males, mean age 72.5 ± 5.3 years, mean serum creatinine 1.9 ± 0.6 mg/dl) underwent endovascular repair of PVD before coronary surgery, following specific indications. High-risk definitions included: > 3-vessel CAD, including the left anterior descending coronary artery or the left main trunk, > 3 risk factors, including diabetes, ejection fraction 1.5 mg/ml, > 75 years old, and previous cardiac surgery or percutaneous coronary revascularization. For each patient, diagnostic methods, indications for intervention, types of interventions, procedural success, and complications were recorded. Results. Four clinical settings were identified: renal artery stenting prior to coronary surgery (7 patients); iliac artery angioplasty and stenting (6 patients) (in order to facilitate aortic balloon pump insertion after surgery); subclavian artery angioplasty and stenting propaedeutical to arterial conduits bypass surgery (1 patients); and carotid artery stenting before coronary surgery (2 patients). Technical success was achieved in all patients (100%). Complications included contrast nephropathy (3 patients) and minor bleeding at the puncture site (2 patients). All patients underwent successful coronary surgery; no patients died intra-perioperatively. At a mean follow-up of 16.6 ± 9.1 months, all patients were alive and free from anginal symptoms, with no clinical or Doppler ultrasonography evidence of restenosis of the implanted stents. Conclusion. It is not unusual for high-risk patients who are candidates for coronary surgery to require an endovascular intervention for significant PVD in order to improve coronary surgery safety and feasibility. Preliminary results in this small series are encouraging, with an acceptable complication rate. The cardiologist may play an important role in regards to not only the diagnosis of vascular distribution, which should be extended to all patients with significant CAD, but also in regard to the endovascular management of high-risk patients.

There are various reasons why interventional cardiologists are opting for a more global approach to patients with peripheral vascular disease (PVD). Coronary artery disease (CAD) is frequently associated with extra-cardiac atherosclerosis,^1–3 PVD negatively impacts the prognosis of patients with CAD and ischemic heart disease,^4–5 and finally, the increasing age of the population makes multiple vascular atherosclerotic distributions more likely to be found in patients who are candidates for coronary surgery.⁶ Whether high-risk patients with PVD who are candidates for surgical myocardial revascularization may benefit from endovascular treatment prior to coronary surgery is still debatable. We sought to identify the most frequent clinical settings requiring propaedeutical endovascular treatment before coronary surgery, results, and impact on subsequent surgical revascularization in such high-risk patients.

Material and Methods

Between November 2000 and November 2004, 16 high-risk patients (9 males, mean age 72.5 ± 5.3 years, mean serum creatinine 1.9 ± 0.6 mg/dl, underwent endovascular repair of PVD propaedeutical to coronary surgery related to specific indications. Informed consent was obtained from all patients. High-risk definitions included: 1) > 2-vessel CAD, including the left anterior descending coronary artery or left main trunk; 2) > 3 risk factors; 3) Ejection fraction 1.5 mg/ml. Additional criteria were: 5) > 75 years old; 6) Previous cardiac surgery; 7) Previous vascular surgery; 8) Previous endovascular or percutaneous myocardial revascularization. For each patient, diagnostic method, indications for intervention, types of interventions, procedural success and complications were recorded. Our institutional policy includes a noninvasive screening for extracardiac atherosclerotic distributions in all patients with significant CAD by means of Doppler ultrasonography of epiaortic vessels and peripheral arteries. According to this policy, the diagnosis was guided by previous noninvasive technique and confirmed during coronary angiography in 6 patients: renal Doppler ultrasonography for abdominal bruit and uncontrolled hypertension (4 patients), ultrasonographic follow-up of previous iliac artery endovascular interventions (1 patient), and carotid artery Doppler ultrasonography (1 patient). Diagnosis was made at the time of coronary angiography in 10 patients. Subclavian artery angiography was used to assess LIMA suitability and prevent subclavian coronary steal syndrome in 1 candidate for arterial conduits, based on subclavian bruit and blood pressure differential > 20 mmHg. Diagnosis was made by aortoiliac angiography in 9 patients based on abdominal bruit (1 patient), on systolic blood pressure > 180 mmHg and diastolic blood pressure > 110 mmHg, regardless of anti-hypertensive drugs (4 patients), flashing edema (2 patients), and unexplained renal dysfunction (2 patients). Contrast-induced nephropathy was defined as a rise in serum creatinine of > 25% from baseline. Minor bleeding was defined as bleeding that does not require blood transfusions. Follow-up was accomplished by means of 3-, 6-, and 12-month visits, and a 6- and 12-month stress test (treadmill test or nuclear stress tests). Surveillance of the implanted stent was performed by 6- and 12-month Doppler ultrasonography examination.

Results

We identified four clinical settings: 1) Renal artery stenting prior to coronary surgery (7 patients); 2) Iliac artery artery angioplasty and stenting (6 patients) in order to facilitate aortic balloon pump insertion after surgery; 3) Subclavian artery angioplasty and stenting propaedeutical to arterial conduits bypass surgery (1 patient); 4) Carotid artery stenting before coronary surgery (2 patients). Endovascular intervention was indicated if a patient had an extremely high risk for vascular surgery or a need for urgent coronary surgery. For renal angioplasty, the main indications for endovascular intervention were to prevent in-hospital acute renal failure in 2 patients with worsening of renal function not due to contrast nephropathy and in 4 patients, bilateral renal artery disease with moderate renal failure. For iliac stenting, the indication was significant bilateral disease, in order to facilitate usage of an intraaortic balloon pump. For carotid artery stenting, the indication was a significant carotid disease in 2 patients in whom surgery could be reasonably delayed 3 weeks. For subclavian artery stenting, the indication was significant left subclavian artery disease, and the unsuitability of other arterial conduits, leading to use of the left internal mammary artery as a graft. Renal artery stenting was performed through an ipsilateral femoral approach and standard RDC guiding catheter in 5 patients. We utilized a radial approach with a MPA guiding catheter in 2 patients due to the downward origin of the vessel. Direct stenting with the Genesis™ stent (Cordis Endovascular, Johnson & Johnson, Warren, New Jersey) or Driver stent (Medtronic, Inc., Santa Rosa, California) was preferred. Protection with the PercuSurgesystem (PercuSurge Inc., Sunnyvale, California) was used in 1 patient. A retrograde ipsilateral approach was employed for iliac artery angioplasty and stenting using a 23 cm Brite Tip 8 or 9 Fr introducer (Cordis, Johnson & Johnson) and Genesis or Symphony stents (Boston Scientific Europe, Paris, France). Subclavian and carotid artery stenting were performed using the right femoral approach and standard sidewinder or multi-purpose 8 Fr guiding catheter with hydrophilic 0.018-inch guidewire to deploy a Genesis and Cordis nitinol carotid stent (Cordis, Johnson & Johnson), respectively. No protection device was used due to the difficult anatomy of the vessel. Hemostasis was successfully accomplished with a VasoSeal® (Datascope, Mahwah, New Jersey) device in all femoral approaches. Special care allowed us to lower the contrast dose to Discussion Patients with PVD undergoing coronary revascularization have a high rate of adverse outcomes, since diabetes, chronic renal dysfunction, old age and PVD greatly affect survival after both coronary surgery and percutaneous revascularization.7–9 The interventional cardiologist often has to deal with high-risk complex patients with PVD, multiple risk factors, and low ejection fraction, patients in whom the endovascular treatment of PVD may decrease the risks and improve the results of a subsequent coronary artery bypass intervention. Chronic renal ischemia caused by atherosclerotic renal artery stenosis (RAS) is gaining recognition as a potentially important risk factor for cardiovascular morbidity and mortality. The etiology of the increased risk of cardiovascular events is multi-faceted, and includes direct physiological changes that increase risk, as well as intermediate clinical effects that are associated with negative outcome.¹⁰ Even mild chronic kidney disease is associated with an increased risk of recurrent hospitalization, subsequent CABG and mortality.¹¹ Revascularization of a stenosed renal artery is associated with preservation of renal function and better control of hypertension, unstable angina and congestive heart failure.¹² Preventive stent placement may reduce perioperative renal deterioration in this specific group of patients like those at high-risk,¹³ as already described by Sullivan et al.¹⁴ regarding aortic aneurysm repair. Similarly, it is important for the interventional cardiologist to recognize and treat aortoiliac disease on the basis of three points: 1) The long-term morbidity is higher and survival ratio poor in patients with CAD, compared with isolated lower extremity revascularization surgery; 2) Coronary surgery is a relatively high-risk procedure in patients with severe vascular disease; 3) The limitation for future perioperative intra-aortic balloon placement.^15–16 Preventive angioplasty and stenting of iliac or femoral arteries associated with contralateral disease or severe kinking, which are contraindications for an intraaortic balloon pump, may offer the cardiac surgeon an access site for systolic assistance in the preoperative period in order to improve revascularization results in patients with low ejection fraction.¹⁷ Proximal subclavian artery occlusive disease associated with a patent internal mammary artery used as a conduit for a coronary artery bypass graft procedure may cause the reversal of the internal mammary artery flow (coronary-subclavian steal), leading to myocardial ischemia.18 In order to prevent this catastrophic occurrence, all patients undergoing cardiac catheterization prior to coronary artery bypass grafting using the internal mammary artery should be evaluated for upper extremity and cerebrovascular ischemia, cervical or supraclavicular bruits, and an upper extremity blood pressure differential of 10–20 mm Hg or greater.¹⁹ Patients with these findings or with evidence of diffuse atherosclerotic vascular disease should have brachiocephalic arteriography at the time of coronary arteriography to identify significant subclavian artery occlusive disease.20 In high-risk patients, angioplasty and stenting of the subclavian artery may prevent any subclavian coronary steal syndrome and make the internal mammary artery suitable as an arterial conduit.^21–22 Up to 12% of patients presenting for coronary bypass have critical carotid disease, and more than 50% of patients presenting for carotid endarterectomy have significant coronary disease. Patients requiring surgery for both carotid and coronary disease may be managed with carotid endarterectomy, followed by coronary bypass (staged approach), with coronary bypass followed by carotid endarterectomy (reversed staged approach), or with simultaneous coronary bypass-carotid endarterectomy. There are no compelling data proving the superiority of any of these three approaches.^23–24 Management of patients with advanced atherosclerosis involving the extra-cranial carotid and coronary arteries should be personalized on the basis of symptoms and disease severity. A liberal policy to identify high-grade carotid stenosis using duplex ultrasound testing prior to coronary revascularization is recommended. Carotid angioplasty with cerebral protection may be an appropriate option in “high-risk” cardiac patients, especially in vascular centers with expertise and experience in performing this procedure.^25–27 Although no definitive data can be drawn from this small, anecdotal preliminary experience, our study suggests that endovascular treatment of PVD in high-risk patients candidates for coronary surgery may be effective, relatively safe and lasting, in spite of alow-dose antiplatelet regimen. Further studies should be performed in order to fully evaluate the impact on long-term outcomes. The interventional cardiologist may play an important and active role in both the diagnosis and treatment of patients who would require a more global cardiovascular management. In this scenario, the cardiologist should work as a full cardiovascular specialist. A more extensive policy of noninvasive vascular screening in patients with significant CAD should be recommended.

Address for correspondence: Gianluca Rigatelli, MD, EndoCardioVascular Therapy Research, Via T. Speri 18, 37040 Legnago, Verona, Italy. Email: jackyheart@hotmail.com