Savvas Savvidis

Different Calculations of Ankle-Brachial Index and Their Impact on Cardiovascular Risk Prediction

Background— An ankle-brachial index (ABI; ratio of ankle and brachial systolic blood pressure) <0.9 indicates peripheral arterial disease (PAD) and is a strong predictor of cardiovascular events. The aim of the present study was to address the prognostic value of different methods of ABI calculation. Methods and Results— In 831 patients admitted with chest pain for diagnostic heart catheterization, blood pressure of both anterior and posterior tibial arteries was measured. ABI was calculated for each leg with the higher of the 2 ankle pressures (current definition of the American Heart Association) or with the lower of the 2 ankle pressures (modified definition) in relation to the higher of the left or right brachial systolic blood pressure. For each patient, the lower ABI from both legs was used for further evaluation. Fifteen patients (1.8%) with ABI >1.5 were excluded. We compared patients with ABI <0.9 according to the current definition (with PAD, n=204 [25.0%]), those with ABI ≥0.9 according to the modified definition (without PAD, n=524 [64.2%]), and those with ABI <0.9 according to the modified definition and ≥0.9 according to the current definition (suspected PAD, n=88 [10.8%]). Follow-up data (median 6.6 years) were available for 812 patients (99.5%); 157 patients (19.3%) experienced cardiovascular events (cardiovascular death, myocardial infarction, or stroke). Patients without PAD had the lowest cardiovascular event rate, whereas event rates were comparable for patients with PAD and those with suspected PAD (14.8% versus 28.4% versus 25.0%, respectively). In a fully adjusted Cox regression analysis that included patients without PAD as the reference group, the hazard ratio (95% CI) was 1.56 (0.97 to 2.53) for patients with suspected PAD and 1.67 (1.16 to 2.40) for patients with PAD. Conclusions— When the higher ankle pressure is used for ABI calculation, a group of patients at high risk for cardiovascular events is overlooked. With a simple modification of ABI (use of the lower instead of the higher ankle pressure), more patients at risk could be identified.

β-Blockers in Patients With Intermittent Claudication and Arterial Hypertension Results From the Nebivolol or Metoprolol in Arterial Occlusive Disease Trial

The use of &bgr;-receptor blockers in peripheral arterial disease is controversial for their impact on vasomotor tone. The &bgr;-blocker nebivolol possesses vasodilating, endothelium-dependent, NO-releasing properties that might be beneficial in peripheral arterial disease. The aim of the study was to evaluate the effects and tolerability of nebivolol in comparison with metoprolol in these patients. A total of 128 patients with intermittent claudication and essential hypertension were included and double-blind randomized to receive 5 mg of nebivolol (N=65) or 95 mg of metoprolol (N=63) once daily. End points were changes in ankle-brachial index, initial and absolute claudication distance, endothelial function assessed by flow-mediated dilatation of the brachial artery, blood pressure, and quality of life using the claudication scale questionnaire. End point analysis was possible in 109 patients (85.2%). After the 48-week treatment period, ankle-brachial index and absolute claudication distance improved significantly in both patient groups (P<0.05 for both), with no difference across treatments. A significant increase of initial claudication distance was found in the nebivolol group. Adjusted mean change of initial claudication distance was 33.9% after nebivolol (P=0.003) and 16.6% after metoprolol (P=0.12) treatment. Quality of life was not influenced by either treatment, and there was no relevant change in flow-mediated dilatation in patients treated with nebivolol or metoprolol (P=0.16). Both drugs were equally effective in lowering blood pressure. In conclusion, &bgr;-blocker therapy was well tolerated in patients with intermittent claudication and arterial hypertension during a treatment period of ≈1 year. In the direct comparison, there was no significant difference between nebivolol and metoprolol.

Outcomes of complex femorodistal sequential autologous vein and biologic prosthesis composite bypass grafts

OBJECTIVE Femorodistal autologous vein bypass proves to be the preferred surgical therapy for long arterial occlusions and provides excellent early and long-term results in critical lower limb ischemia. Whenever vein length was insufficient and two distal outflow arteries were present, a sequential composite bypass configuration was chosen with human umbilical vein (HUV) or ovine collagen prosthesis (Omniflow II; Bio Nova International Pty Ltd, North Melbourne, Australia) as the proximal prosthetic part of the bypass. Single-center experience with this technique regarding limb salvage, graft function, secondary reinterventions, and biodegeneration is presented. METHODS Between January 1998 and January 2009, 122 consecutive sequential composite bypass operations were performed on 116 patients for short-distance claudication (2), chronic critical ischemia (117), or acute ischemia (3) in the absence of sufficient autologous vein length. HUV was used in 90 cases and Omniflow II in 32 cases. Grafts were followed by duplex scan supplemented by angiography in case of recurrent ischemia with prospective documentation of follow-up data in a computerized vascular database. Retrospective analysis of graft patency, limb salvage, and aneurysmal degeneration of the biologic prosthesis was performed. RESULTS Mean follow-up was 59 ± 45.5 months (range, 1-161 months). The 30-day mortality was 4.1%. Early postoperative complete or partial bypass thrombosis developed in 16% (20 cases) and required successful revision in 16 cases. During follow-up, 30 complete and 12 partial bypass occlusions occurred, necessitating selective surgical or interventional revision. Primary, primary assisted, and secondary patency rates and the limb salvage rate were 48%, 62%, 71%, and 87%, respectively, after 5 years and 26%, 46%, 54%, and 77%, respectively, after 10 years for all bypasses. Late biodegeneration of HUV prostheses was detected in four instances. CONCLUSIONS Late graft patency and limb salvage were good. These factors, combined with a tolerable rate of late aneurysmal degeneration, justify the use of biologic vascular conduits and autologous vein for complex femorodistal reconstructions.

Questionable value of adjuvant arteriovenous fistula in pedal bypass at high risk for early failure.

Results of an adjuvant arteriovenous fistula (AVF) in pedal bypass surgery in the presence of poor status of the recipient artery, severely impaired intraoperative runoff, or revision for early failure and flow restitution were analyzed in a retrospective study. From January 1998 to December 2006, 24 adjuvant AVFs were constructed in autologous vein or composite pedal bypasses with low intraoperative bypass flow, poor status of the pedal artery, or during successful early bypass revision to prevent graft failure. All infrainguinal bypass operations were registered in a computerized database and prospectively followed. Pedal bypasses with adjunctive AVF were reviewed for fistula function, graft patency, limb salvage, and patient survival. Primary and secondary bypass patency rates at 1 year were 59% and 77%, respectively, with an AVF patency of 36%. Four legs were amputated despite a patent bypass with patent AVF on three occasions. The corresponding limb salvage rate was 65% at 1 year. Patient survival was 50% at 3 years. Adjuvant AVF constructed in grafts considered at high risk for early failure in pedal vein graft or composite bypass does not seem to prevent future graft failure. In patent bypasses the fistula has a significant tendency for spontaneous occlusion. It may be considered in the use of prosthetic composite pedal grafts in selected cases.

Very distal vein bypass in patients with thromboangiitis obliterans

BACKGROUND Surgical revascularization for chronic critical limb ischaemia in patients with thromboangiitis obliterans (TAO) still remains controversial. Generally, besides cessation of smoking, conservative treatment supported by intravenous administration of vasoactive agents is regarded as the treatment of choice, in combination with local wound therapy or minor amputation. PATIENTS AND METHODS In four male patients (42-47 years) surgical revascularization was chosen as therapy for established gangrene or non-healing ulceration after unsuccessful conservative treatment and cessation of smoking. Angiography was able to identify a suitable distal arterial segment for the bypass which was revascularized by means of an autologous vein graft. Grafts were followed with repetitive duplex ultrasound. Revision of the bypass graft was initiated if indicated by pathological duplex findings. RESULTS In all cases a bypass could be constructed with either the ipsilateral greater saphenous vein or arm veins. A distal origin configuration was possible in three cases with popliteo-pedal or cruro-pedal bypasses. In the fourth case the distal superficial femoral artery was used for inflow. Two early graft thromboses underwent successful revision. During follow-up, duplex ultrasound identified graft stenoses in three bypasses which were successfully treated with endovascular techniques. All grafts are patent with complete resolution of ischaemic symptoms after 46, 42, 32, and 29 months. The patients remained non-smokers and returned to a professional life. CONCLUSIONS Surgical therapy with distal vein bypass for persistent ischaemic symptoms after definitive cessation of smoking seems feasible in selected cases with TAO and a suitable distal artery. Close follow-ups of the patients with duplex ultrasound are necessary to identify developing vein graft stenoses. Angioplasty seems to be an important part of the long-term therapeutic concept.

External polytetrafluoroethylene reinforcement of varicose autologous vein grafts in peripheral bypass surgery produces durable bypass function

Objective: Use of autologous veins as peripheral bypass graft may become critical in the presence of significant varicose degeneration of the harvested vein. External support of such dilated veins with standard polytetrafluoroethylene (PTFE) prostheses was recommended as an option to use these veins for peripheral bypass. A single‐center experience with this technique regarding long‐term graft function, secondary reinterventions, and potential graft degeneration is presented. Methods: Between January 1995 and January 2006, there were 54 patients with varicose veins who underwent 57 consecutive infrainguinal vein bypass operations with PTFE reinforcement in 57 limbs. Indications for surgery consisted of disabling claudication (5), chronic critical ischemia (40), popliteal aneurysm (11), and acute ischemia (1). Grafts were observed with duplex ultrasound scan supplemented by additional angiography in case of recurrent ischemia, with prospective documentation of follow‐up data in a computerized vascular database. Graft patency, limb salvage, and possible degeneration of the vein grafts were retrospectively analyzed. Results: Mean follow‐up was 79 months (range, 1–219 months). The 30‐day mortality was 2%. Secondary procedures to maintain or to restore bypass patency were necessary in 12 grafts (21%). Primary, primary assisted, and secondary patency rates were 54%, 73%, and 73% after 5 years for all bypasses, with a limb salvage rate for limbs operated on for chronic critical or acute ischemia of 83%. Significant stenosis of a reinforced vein segment was detected in one case after 56 months, with subsequent replacement of the vein graft with a biologic vascular prosthesis. Conclusions: Good late graft patency and limb salvage combined with a low rate of late vein graft degeneration justify the use of external PTFE reinforcement of varicose vein segments in infrainguinal bypass surgery.

Response to Letter Regarding Article, “Different Calculations of Ankle Brachial Index and Their Impact on Cardiovascular Risk Prediction”

We thank Jaquinandi et al for their interest in our publication. We want to stress that the patient population of the AtheroGene study is not comparable with the patient populations reported in the articles from Lee et al and Kreitner et al, which included only patients with known advanced peripheral arterial disease.1,2 The AtheroGene study includes primarily patients with coronary artery disease, no patient had rest pain or peripheral ulcers and only 52 patients (6.3%) had intermittent claudication.3 In addition, …