Long-term clinical outcomes and cardiovascular events after carotid endarterectomy

BACKGROUND

Long-term atherosclerotic adverse events are anticipated in patients undergoing carotid endarterectomy (CEA); however, their incidence and risk predictors remain unknown.

METHODS

A consecutive cohort of CEAs between 1/1/2000-12/31/2007 was analyzed. End points were any stroke, coronary event (myocardial infarction, coronary bypass, or stenting), vascular interventions for critical limb ischemia, aortic aneurysm or carotid disease, and death. Survival analysis and Cox regression models were used to identify clinical predictors.

RESULTS

A total of 1,136 CEAs (bilateral, 89; mean age, 71.2 ± 9.2 years; 56.5% male; 36.3% symptomatic, and 3.9% combined with coronary bypass) were performed during the study period with a mean clinical follow-up of 60 months (0-155 months). The postoperative combined stroke and/or death rate was 2.7% and 1.9% for asymptomatic and 4.1% for symptomatic patients. Five and 10-year risks of the end points were 7.2% and 16.1% for stroke, 18.4% and 31.5% for coronary interventions, 20.6% and 28.5% for major vascular interventions, and 25.8% and 50.1% for death. Statins conferred a significant protective effect for stroke (hazard ratio [HR], 0.53; P = 0.016) and death (HR, 0.66; P < 0.0001). Baseline vascular disease predicted future vascular interventions: aortic aneurysm (HR, 1.90; P = 0.003), peripheral arterial disease (HR, 2.03; P < 0.0001), and contralateral internal carotid artery (ICA) stenosis ≥50% (HR, 4.61; P < 0.0001). Renal insufficiency predicted worse outcomes for all other end points (HR, 2.21; P = 0.023 for stroke; HR, 1.62; P = 0.008 for coronary events; HR, 2.38; P < 0.0001 for death).

CONCLUSIONS

Patients undergoing CEA continue to derive long-term low stroke rate benefit but still sustain major coronary events and require vascular interventions, indicating a need for more intensive medical treatment and rigorous follow-up.

Autologous alternative veins may not provide better outcomes than prosthetic conduits for below-knee bypass when great saphenous vein is unavailable

BACKGROUND

There is a need to better define the role of alternative autologous vein (AAV) segments over contemporary prosthetic conduits in patients with critical limb ischemia when great saphenous vein (GSV) is not available for use as the bypass conduit.

METHODS

Consecutive patients who underwent bypass to infrageniculate targets between 2007 and 2011 were categorized in three groups: GSV, AAV, and prosthetic. The primary outcome was graft patency. The secondary outcome was limb salvage. Cox proportional hazards regression was used to adjust for baseline confounding variables.

RESULTS

A total of 407 infrainguinal bypasses to below-knee targets were analyzed; 255 patients (63%) received a single-segment GSV, 106 patients (26%) received an AAV, and 46 patients (11%) received a prosthetic conduit. Baseline characteristics were similar among groups, with the exception of popliteal targets and anticoagulation use being more frequent in the prosthetic group. Primary patency at 2 and 5 years was estimated at 47% and 32%, respectively, for the GSV group; 24% and 23% for the AAV group; and 43% and 38% for the prosthetic group. Primary assisted patency at 2 and 5 years was estimated at 71% and 55%, respectively, for the GSV group; 53% and 51% for the AAV group; and 45% and 40% for the prosthetic group. Secondary patency at 2 and 5 years was estimated at 75% and 60%, respectively, for the GSV group; 57% and 55% for the AAV group; and 46% and 41% for the prosthetic group. In Cox analysis, primary patency (hazard ratio [HR], 0.55; P < .001; 95% confidence interval [CI], 0.404-0.758), primary assisted patency (HR, 0.57; P = .004; 95% CI, 0.388-0.831), and secondary patency (HR, 0.56; P = .005; 95% CI, 0.372-0.840) were predicted by GSV compared with AAV, but there was no difference between AAV and prosthetic grafts except for the primary patency, for which prosthetic was protective (HR, 0.38; P < .001; 95% CI, 0.224-0.629). Limb salvage was similar among groups.

CONCLUSIONS

AAV conduits may not offer a significant patency advantage in midterm follow-up over prosthetic bypasses.

Arteriovenous grafts are associated with earlier catheter removal and fewer catheter days in the United States Renal Data System population

OBJECTIVE

Arteriovenous fistulas (AVFs) are associated with improved long-term outcomes but longer maturation times and higher primary failure rates compared with arteriovenous grafts (AVGs). The Fistula First Breakthrough Initiative has recently emphasized tunneled dialysis catheter (TDC) avoidance. We sought to characterize the relationship of AVFs and AVGs to the use of TDCs as well as secondary procedures.

METHODS

Using the United States Renal Data System (USRDS) database, we identified incident hemodialysis (HD) patients in 2005 that started HD with a TDC and survived at least 1 year. We then monitored them through 2008. Access creation, TDC removal, TDC placement, and secondary procedures were identified by Current Procedural Terminology codes (American Medical Association, Chicago, Ill). Multivariate logistic regression was used to identify risk factors for the primary end points.

RESULTS

In 2005, HD was initiated in 56,495 patients, 74% with a TDC. Of these, 6286 had an access procedure ≤3 months and 1 year of follow-up (AVF, 4634; AVG, 1652). Mean age was 67.7 years (AVF, 67.3; AVG, 68.7 years; P < .001), 53.3% were men (AVF, 58.1%; AVG, 40.5%; P < .001), and 33.8% were obese (AVF, 33.6%; AVG, 34.4%; P = not significant). AVG placement was associated with a higher TDC removal at 1 (7.9% vs 3.1%; P < .001), 3 (47.8% vs 17.8%; P < .001), and 6 (60.6% vs 47.2%; P < .001) months. There was no difference at 9 months (AVG, 64.9% vs AVF, 62.3%; P = .06). The median time to TDC removal was lower in the AVG group (70 days vs 155 days; P < .001). Multivariable model found AVFs were associated with decreased odds of TDC removal at 3 (odds ratio, 0.22; P < .001) and 6 months (odds ratio, 0.54; P < .001). AVGs required more secondary procedures than AVFs at all time points up to 1 year and specifically had increased thrombectomy procedures (39.8% vs 11.5%; P < .001).

CONCLUSIONS

In patients starting dialysis with a TDC, AVGs are associated with increased TDC removal and fewer catheter days compared with AVFs at up to 6 months. However, AVGs require more secondary procedures at all time points up to 1 year.

Limited survival in dialysis patients undergoing intact abdominal aortic aneurysm repair

OBJECTIVE

Elective abdominal aortic aneurysm (AAA) repair in suitable candidates is a standard modality. The outcomes of AAA repair in patients with end-stage renal disease on dialysis are not well characterized, and there is questionable survival advantage in such patients with limited life expectancy. We sought to describe outcomes after AAA repair in U.S. dialysis patients.

METHODS

The United States Renal Data System was used to collect data on intact asymptomatic AAA repair procedures in dialysis patients in the United States between 2005 and 2008. Endovascular AAA repair (EVAR) and open aortic repair (OAR) were identified by Current Procedural Terminology codes. Primary outcomes were perioperative (30-day) mortality and long-term survival. Predictors of mortality were identified by multivariate regression models.

RESULTS

A total of 1557 patients were identified who had undergone elective AAA repair: 261 OAR and 1296 EVAR. The 30-day mortality was 11.3% (EVAR, 10.3%; OAR, 16.1%; P = .010), with increased age associated with increased mortality (odds ratio, 1.04; 95% confidence interval [CI], 1.02-1.07; P = .001). Kaplan-Meier survival estimates were 66.5% at 1 year (EVAR, 66.2%; OAR, 68%) and 37.4% at 3 years (EVAR, 36.8%; OAR, 40%; P = .33). Median survival was 25.3 months after EVAR and 27.4 months after OAR. Women had a higher mortality rate at 1 year (38.7%) compared with men (32.0%) (P = .015). There was no significant mortality difference at 1 year in comparing type of procedure in both men (EVAR, 31.6%; OAR, 34%; P = .55) and women (EVAR, 39.3%; OAR, 36%; P = .60). A Cox proportional hazards model demonstrated that male gender (hazard ratio [HR], 0.75; 95% CI, 0.62-0.92; P = .005), increased time on dialysis (HR for each year on dialysis, 0.79; 95% CI, 0.75-0.83; P < .001), kidney transplantation history (HR, 0.62; 95% CI, 0.43-0.88; P = .008), and diagnosis of hypertension (HR, 0.60; 95% CI, 0.48-0.75; P < .001) were protective against mortality. Increased age (HR, 1.02; 95% CI, 1.01-1.03; P < .001) and diabetes diagnosis (HR, 1.39; 95% CI, 1.13-1.71; P = .002) predicted increased mortality.

CONCLUSIONS

AAA patients on dialysis have high perioperative and 1-year mortality rates after EVAR or OAR, particularly diabetics, women, and the elderly. This raises questions about the indications for intact AAA repair in dialysis patients, in whom the size threshold may need to be raised. Dialysis patients may be best served by deferring repair of AAA until AAAs reach large size or become symptomatic, especially if OAR is required, given the higher perioperative mortality compared with EVAR.

Cryoplasty offers no advantage over standard balloon angioplasty for the treatment of in-stent stenosis

In-stent restenosis is the primary failure mode of endovascular treatment of occlusive disease in the femeropopliteal segment. Cryoplasty has been proposed to reduce intimal hyperplasia through induction of apoptosis. We sought to evaluate the efficacy of cryoplasty for treatment of in-stent restenosis compared to conventional balloon angioplasty (CBA). After IRB approval, a retrospective record review was performed of reinterventions for in-stent restenosis by a single vascular surgery group at a university hospital. Reinterventions involving cryoplasty and CBA were evaluated at 1, 3, 6 and 12 months after intervention with duplex imaging to identify significant recurrent stenosis utilizing established velocity criteria. Data collected included basic demographic information and comorbidities as well as time to restenosis. Statistical analysis was performed using Kaplan–Meier survival curves with the log rank test, Wilcoxon rank test, and Cox proportional hazards models. From December 2004 to November 2007, 76 reinterventions were performed using CBA (n = 39) or cryoplasty (n = 37) for in-stent restenosis without placement of additional stents. Periprocedural technical success (>30% residual stenosis) was 100% for both groups, with no complications. The two cohorts were statistically similar in mean age, gender, comorbidities, tobacco use and use of statins, aspirin and Plavix. However, the mean lesion length was significantly longer in the cryoplasty cohort (CBA: 140.9 mm, Cyro: 191.7 mm; P = 0.032). The mean time to recurrent stenosis or need for additional secondary intervention was significantly shorter for the cyroplasty cohort than for the CBA, 4.09 and 10.79 months, respectively ( P = .0001). Recurrent stenosis-free survival was significantly lower in the cyroplasty cohort at 3 months (CBA: 96.9%, Cyro: 88.9%) and 6 months (CBA: 84.0%, Cyro: 43.8%; P = .0089). Cyroplasty as a modality for treatment of in-stent stenosis in the femoropopliteal segment offers no benefit over CBA.

Predictors and outcomes of restenosis following tibial artery endovascular interventions for critical limb ischemia

OBJECTIVE

Restenosis following tibial artery endovascular interventions (TAEIs) is thought to be benign but is not well characterized. This study examines the consequences and predictors of recurrent stenosis of TAEIs for critical limb ischemia.

METHODS

All TAEIs for critical limb ischemia performed between 2004 and 2010 were retrospectively reviewed. Restenosis was detected by noninvasive imaging and angiography when indicated. Restenoses were identified and the limb outcomes recorded. Tibial reinterventions were performed only for persistent, worsening, or recurrent tissue loss or rest pain with evidence of recurrence on duplex ultrasound or hemodynamic imaging. The χ test and logistic regression were applied as indicated. One-year patency rates were calculated using the Kaplan-Meier method.

RESULTS

A total of 235 limbs in 210 patients were treated for critical limb ischemia (70% tissue loss, 30% rest pain). Tissue loss included gangrene (49%) and ulcers (51%), and involved the forefoot (80%), the heel (14%), or both (6%). Seventy-eight percent of limbs had Trans-Atlantic InterSociety Consensus C/D lesions, with mean preoperative runoff score of 12. Interventions were isolated tibial (45%) or multilevel (55%) (including tibial). Mean postoperative runoff score improved to 6.6, but restenosis occurred in 96 limbs (41%) at a mean of 4 months. The 1-year primary patency was 59% with a mean follow-up of 9 months. Restenosis presented with a persistent wound (32%), worsened wound (42%), rest pain (16%), or no symptoms (10%). A repeat TAEI was performed in 42 (44%), major amputation in 26 (27%), open bypass in 20 (21%), and observation in eight (8%). The overall amputation rate was 13%, but limb loss was significantly higher in patients with restenosis (n = 26 [27%]) than in patients with no restenosis (n = 5 [4%]; P < .001). Patients with restenosis and tissue loss were more likely to have presented with gangrene (63% vs 38%; P = .0003) but had comparable wound distribution (P = NS). There was a trend toward a higher restenosis rate in patients with renal insufficiency (odds ratio, 5.57; P = .08), but this was unaffected by diabetes, statin therapy, or smoking (P = NS). The rate of repeat intervention after the first reintervention was 36%, with an 87% overall limb salvage rate.

CONCLUSIONS

TAEIs can be used successfully to treat patients with critical limb ischemia with acceptable limb salvage rates. Special attention should be given to patients with extensive tissue loss or gangrene because they are at risk for early restenosis and subsequent limb loss. Strict wound and hemodynamic surveillance, wound care, and timely reinterventions are crucial to achieve successful outcomes in this patient population. Amputation or alternative revascularization options, when feasible, should be considered in patients with restenosis and tissue loss given the high rate of limb loss with tibial reinterventions.

Patterns of femoropopliteal recurrence after routine and selective stenting endoluminal therapy

OBJECTIVE

This study determined the incidence and characteristics of recurrent disease after femoropopliteal angioplasty, following either selective or routine stenting of diseased site(s).

METHODS

Retrospective analysis of a prospectively maintained database for femoropopliteal interventions from June 2003 to July 2010 was performed. Interventions during this period were from a single institution, followed up at 1, 3, and 6 months after initial intervention and on a semiannual basis thereafter with clinical examinations and duplex ultrasound imaging. Two groups were identified: those with routine stenting (RS; routine stenting for all diseased areas) and those with selective stenting (SS; selective stenting for only segments which exhibited compromised flow from residual stenosis or significant dissection). Patients who developed recurrent symptoms (claudication, rest pain), a decrease in ankle-brachial index (ABI) (>0.2), or duplex documentation of a significant (>80%) recurrent stenosis underwent reintervention. Patient demographics, comorbidities, Trans-Atlantic Inter-Society Consensus (TASC) II classification, runoff, and degree of calcification (none, mild, moderate, severe) at initial intervention were recorded. The time to reintervention and recurrence pattern were recorded for both groups.

RESULTS

During the study period, 746 endovascular interventions in 477 patients were performed. Total reintervention rate, including bypass, amputation, and asymptomatic occlusion after initial intervention, was 36.48% (group SS, 42.9%; group RS, 33.1%; P=.04). Of all initial interventions, 182 endovascular reinterventions in 165 patients for recurrent femoropopliteal disease were identified (group SS, 70; group RS, 95). No differences were noted among the groups in gender, comorbidities, initial TASC II classification, run off, calcification scores, or statin or clopidogrel use, or both. Time to recurrence was similar in the RS and SS groups. TASC II classification, runoff score, and degree of calcification were similar between the two groups. Although not statistically significant, analysis of recurrence pattern demonstrated de novo stenosis was more common in the SS group (50.0% vs 34.7%; P=.06).

CONCLUSIONS

This single-center retrospective study found a significant difference in the incidence of recurrence requiring reintervention between patients treated with selective and routine stenting for femoropopliteal disease. Analysis of endovascular reinterventions, however, reveals no significant difference in recurrence time or recurrence pattern between the two groups. No significant differences were identified in time to recurrence, TASC II classification, runoff, and calcification of endovascular reinterventions between the two groups' end points. Additional prospective studies to evaluate the roles of routine and selective stenting in symptomatic femoropopliteal peripheral arterial disease and to investigate recurrence lesion characteristics and the patency of multiple endovascular interventions between these two groups are needed.

Endovascular repair of ruptured abdominal aortic aneurysm does not confer survival benefits over open repair

OBJECTIVE

Endovascular repair of ruptured abdominal aortic aneurysm (rAAA) is being increasingly performed despite lack of good evidence for its superiority. Other reported studies suffer from patient selection and publication bias with limited follow-up. This study is a single-center propensity score comparing early and midterm outcomes between open surgical repair (OSR) and endovascular repair of rAAA (REVAR).

METHODS

A retrospective review from January 2001 to November 2010 identified 312 patients who underwent rAAA repairs. Thirty-one patients with antecedent AAA repair and three with incomplete records were excluded, leaving 37 REVARs and 241 OSRs. Propensity score-based matching for sex, age, preoperative hemodynamic status, surgeon's annual AAA volume, and preoperative cardiopulmonary resuscitation was performed in a 1:3 ratio to compare outcomes. Thirty-seven REVARs were matched with 111 OSRs. Late survival was estimated by Kaplan-Meier methods.

RESULTS

Operative time and blood replacement were higher with OSR. Overall complication rates were similar (54% REVAR vs 66% OSR; P = .23), except for higher incidences of tracheostomies (21% vs 3%; P = .015), myocardial infarction (38% vs 18%; P = .036), and acute tubular necrosis (47% vs 21%; P = .009) with OSR. Operative mortality rates were similar (22% REVAR vs 32% OSR), with an odds ratio of 0.63 for REVAR (95% confidence interval = [0.24, 1.48]; P = .40). No differences in the incidences for secondary interventions for aneurysm- or graft-related complications were noted (22% REVAR vs 22% OSR; P = .99). Kaplan-Meier estimates of 1-, 2-, and 3-year survival rates were also similar (50%, 50%, 42% REVAR vs 54%, 52%, 47% OSR; P = .66).

CONCLUSIONS

REVAR for rAAA does not seem to conclusively confer either acute or late survival advantages. Routine use of REVAR should be deferred until prospective, randomized trial data become available.