Preventing spasm of the radial artery conduit during coronary artery bypass grafting: Nicardipine versus verapamil.

BACKGROUND AND AIM OF THE STUDY: In vitro studies have shown a reduction in radial artery spasm with the use of calcium antagonists. The purpose of this study was to evaluate the efficacy of topical treatment of the radial artery conduit using either verapamil or nicardipine before the anastomoses. METHODS: This prospective randomized study included 131 patients, who underwent coronary artery bypass grafting surgery with the use of the radial artery as a conduit. In 65 patients, the harvested radial artery was topically treated with verapamil and in 66 patients with nicardipine. After harvesting the radial artery, the direct flow through the conduit was measured in vitro before 5-minute incubation in nicardipine or verapamil and measured again after incubation. The flow before and after incubation was compared. Postincubation flow was also compared in the two groups. After performing the anastomosis, the flow through the radial artery was measured in vivo. RESULTS: The mean flow after NaCl incubation was 19.93 ± 12.66 mL/min and after incubation in the Ca+ channel blocker 47.16 ± 14.58 mL/min (P < .001). No significant difference in postincubation free flow was found between verapamil (46.29 ± 15.43 mL/min) and nicardipine (48.01 ± 13.77 mL/min; P = .503). CONCLUSION: Topical treatment with Ca+ channel blockers reduces radial artery spasm and significantly increases the free flow through the radial artery conduit. Nicardipine is a safe and effective alternative of verapamil in preventing spasm of radial artery conduit.

A case of right ventricular outflow tract obstruction after minimally invasive aortic valve replacement.

Minimally invasive aortic valve replacement is commonly used to treat aortic valve disease through smaller incisions and upper hemisternotomy. No major differences in postoperative outcomes have been reported compared with full sternotomy aortic valve replacement. In this case report, we present a rare complication of right ventricular outflow tract obstruction after minimally invasive aortic valve replacement.

Preoperative hemoglobin level as a predictor of mortality after aortic valve replacement.

OBJECTIVES: The predictive value of preoperative hemoglobin (HB) level on the outcome of patients undergoing valve surgery is not well established. This study evaluated the predictive value of preoperative HB level on survival after aortic valve replacement (AVR). DESIGN: This was a retrospective analysis of prospectively collected data. SETTING: A single-center study performed in an educational hospital. PARTICIPANTS: All consecutive patients (n = 1,808) who underwent AVR between January 1998 and December 2010. INTERVENTIONS AVR MEASUREMENTS AND MAIN RESULTS: Patients were classified into 4 groups according to the preoperative HB level: very low (HB of <12 g/dL in men and <11 g/dL in women), low (HB of 12-13 g/dL in men and 11-12 g/dL in women), normal (HB of 13-14.5 g/dL in men and 12-13.5 g/dL in women), and high normal (HB of ≥14.5 g/dL in men and ≥13.5 g/dL in women). The mean follow-up duration was 5.58±3.5 years, and the median follow-up duration was 5.38 years. The mean preoperative HB was 14±1.6 g/dL for men and 13.0±2.1 g/dL for women. Early mortality (≤30 days) was 6.1% in the very-low-HB group, 5.4% in the low-HB group, 3.2% in the normal HB group, and 2.3% in the high-normal-HB group (p = 0.37). Late mortality (>30 days) was 26.1% in the very-low-HB group, 23.7% in the low-HB group, 17.1% in the normal-HB group, and 12.6% in the high-normal-HB group (p<0.0001). The multivariate logistic regression model did not identify low HB as an independent predictor for early mortality. Cox regression multivariate analysis revealed both HB level, as a continuous variable, (p = 0.006), and very-low-HB level (p<0.0001), as independent predictors of late mortality. Cox regression analyses, corrected for confounders, demonstrated that low-HB level is an independent predictor for higher overall mortality (hazard ratio = 2.00, CI 1.41-2.85, p≤0.0001). CONCLUSIONS: In patients undergoing AVR, preoperative low-HB level is an independent risk factor for late mortality, but not for early mortality.

Safety of the extended radial artery conduit in performing complete arterial revascularization.

PURPOSE: We have developed a technique to elongate the radial artery (RA) with the distal segment of the left internal thoracic artery. This study investigated the safety and durability of this extended conduit compared with the composite Y-grafts. METHODS: From January 1998 through December 2010, 750 patients underwent complete arterial revascularization with the use of the left internal thoracic artery (LITA) and RA. Out of these patients, 362 patients were operated on with the use of either RA-LITA extension conduit (n = 103), or a composite LITA-RA Y-graft (n = 259) and were included in this study. Cox regression analyses and Kaplan-Meyer survival curves were used to identify the predictive value of the RA-LITA extension technique on both survival and incidence of re-intervention. RESULTS: Cox regression analysis showed that the use of RA-LITA extension conduit was not a significant predictor of re-intervention (p = 0.600) or total survival (p = 0.930).Kaplan-meier curves showed no significant difference between the two groups concerning total survival and re-intervention-free survival (p = 0.600). CONCLUSIONS: Our alternative technique of extending the RA with the distal segment of the LITA is a safe alternative for patients undergoing total arterial revascularization. The long-term survival and incidence of re-intervention is comparable with the composite LITA-RA Y-grafts.

Does the body mass index predict mortality after isolated aortic valve replacement?

BACKGROUND AND AIM OF THE STUDY: Data relating to the impact of body mass index (BMI) on outcomes after isolated aortic valve replacement (AVR) are scarce and controversial. The study aim was to investigate the predictive value of BMI for early and late mortality after isolated AVR. METHODS: Data obtained from patients who underwent isolated AVR between January 1998 and December 2010 at the authors' institution were analyzed retrospectively. Patients were allocated to five groups according to the preoperative BMI: underweight (BMI < 20 kg/m2); normal weight (BMI 20.0-24.9 kg/m2); overweight (BMI 25.0-29.9 kg/m2); obese (BMI 30.0-34.9 kg/m2); and morbidly obese (BMI > 34.9 kg/m2). Logistic and Cox regression analyses were performed to identify the independent predictors of early and late mortality, respectively. RESULTS: After excluding 20 patients who were lost to follow up, and 30 patients with missing preoperative BMI data, a total of 1,758 patients was included in the analysis. The mean follow up was 5.6 +/- 3.5 years (range: 0-13.4 years), and the mean BMI 26.8 +/- 4.3 kg/m2 (range: 17-52 kg/m2). Multivariate logistic regression analyses showed no association between early mortality and the BMI groups. Multivariate Cox regression analyses showed 'underweight' to be an independent predictor for late mortality (hazard ratio 2.89; 95% confidence interval 1.63-5.13, p < 0.0001). CONCLUSION: 'Underweight' is an independent predictor for late mortality after AVR surgery. Morbid obesity did not prove to be predictive of a worse late survival.

Use of extended radial artery conduit for complete arterial revascularization.

We have developed a new technique to elongate the radial artery (RA) with the distal segment of the left internal thoracic artery (LITA). The left anterior descending (LAD) artery is examined to define the site of the LITA-LAD anastomosis and the length of LITA required to perform the anastomosis. The distal segment of the LITA beyond this length is divided in order to elongate the RA. This extended conduit is long enough to perform complete arterial revascularization and to reach the ascending aorta for the proximal anastomosis. Between January 1998 and December 2010, 113 patients were operated on using this technique. There was no early mortality among the whole group. Two patients (1.8%) had perioperative myocardial infarction. Three patients (3.5%) had re-interventions. We conclude that this technique makes the optimal use of both arterial conduits and could be a valuable alternative option for patients who are selected for complete arterial revascularization.

Coronary ischemia due to subclavian stenosis after arterial revascularization.

We describe a case of coronary-subclavian steal in a 60-year-old man who presented with progressive ischemia 16 years after coronary artery bypass with in-situ bilateral internal thoracic artery grafts. Angiography revealed completely patent arterial grafts, but subtotal stenosis of the left subclavian artery. On reoperation, a vein graft was used to connect the aorta to the left internal thoracic artery which was proximally disrupted. No coronary ischemia was found postoperatively.

Hospital outcome after aorta-radial versus internal thoracic artery-radial artery grafts.

BACKGROUND: We researched our data to determine whether use of radial artery (RA) led to similar hospital morbidity as use of pedicled internal thoracic artery (ITA) with vein grafts. We also investigated if use of RA, different RA operative techniques, or number of inflow grafts were predictors for hospital outcome. METHOD: Retrospectively the hospital outcome of the first 512 patients with RAs (RA group) was compared with 108 matched patients with left ITA (LITA) and vein grafts (LITA control group). Two subgroups of RA operative techniques were further analyzed: 327 patients with RA directly from aorta (aorta-RA group), and 185 patients with RA from ITA, as a composite graft, (ITA-RA group). RESULTS: Hospital outcome of the RA group was similar to that of the LITA control group. When all ischemic events (IE) were grouped together, univariate analysis showed that aorta-RA group resulted in less IE than the ITA-RA group (2.1% versus 5.9%, respectively, p = 0.025). Number of inflow grafts did not influence IE. Multivariate analysis, however, did not show that technique of proximal RA anastomosis or number of inflow grafts were predictors for IE. CONCLUSIONS: Hospital outcome after the use of the RA is similar to that of LITA with vein grafts. Univariate analysis shows less IE after direct aorta-RA anastomoses, but multivariate analysis did not show that technique of proximal RA anastomosis and number of inflow grafts are important predictors for hospital outcome.