Del Nido cardioplegia in the setting of minimally invasive aortic valve surgery

The purpose of this study is to report our experience with del Nido cardioplegia (DNC) in the setting of minimally invasive aortic valve surgery. Forty-six consecutive patients underwent minimally invasive aortic valve replacement (AVR) through a “J” ministernotomy: twenty-five patients received the DNC (Group 1) and 21 patients received standard blood cardioplegia (SBC) (Group 2). The rate of ventricular fibrillation at unclamping was significantly lower in the DNC group (12% vs 52%, p=0.004), as well as postoperative creatinine kinase-MB (CK-MB) values (11.4±5.2 vs 17.7±6.9 µg/L, p=0.004). There were no deaths, myocardial infarctions or major complications in either group. Less postoperative use of intravenous insulin (28% vs 81%, p<0.001) was registered in the DNC group. In conclusion, the DNC is easy to use and safe during minimally invasive AVR, providing a myocardial protection at least equivalent to our SBC, improved surgical efficiency, minimal cost and less blood glucose perturbations.

Improvement of aortic valve stenosis by ApoA-I mimetic therapy is associated with decreased aortic root and valve remodelling in mice

BACKGROUND AND PURPOSE

We have shown that infusions of apolipoprotein A-I (ApoA-I) mimetic peptide induced regression of aortic valve stenosis (AVS) in rabbits. This study aimed at determining the effects of ApoA-I mimetic therapy in mice with calcific or fibrotic AVS.

EXPERIMENTAL APPROACH

Apolipoprotein E-deficient (ApoE(-/-) ) mice and mice with Werner progeria gene deletion (Wrn(Δhel/Δhel) ) received high-fat diets for 20 weeks. After developing AVS, mice were randomized to receive saline (placebo group) or ApoA-I mimetic peptide infusions (ApoA-I treated groups, 100 mg·kg(-1) for ApoE(-/-) mice; 50 mg·kg(-1) for Wrn mice), three times per week for 4 weeks. We evaluated effects on AVS using serial echocardiograms and valve histology.

KEY RESULTS

Aortic valve area (AVA) increased in both ApoE(-/-) and Wrn mice treated with the ApoA-I mimetic compared with placebo. Maximal sinus wall thickness was lower in ApoA-I treated ApoE(-/-) mice. The type I/III collagen ratio was lower in the sinus wall of ApoA-I treated ApoE(-/-) mice compared with placebo. Total collagen content was reduced in aortic valves of ApoA-I treated Wrn mice. Our 3D computer model and numerical simulations confirmed that the reduction in aortic root wall thickness resulted in improved AVA.

CONCLUSIONS AND IMPLICATIONS

ApoA-I mimetic treatment reduced AVS by decreasing remodelling and fibrosis of the aortic root and valve in mice.

Effect of Aortic Valve Replacement for Aortic Stenosis on Severity of Mitral Regurgitation

BACKGROUND

Surgically addressing moderate mitral regurgitation (MR) at the time of aortic valve replacement (AVR) for aortic stenosis remains uncertain. The purpose of this study was to examine the change in moderate (2+) or moderate-severe (3+) MR after isolated AVR for aortic stenosis to determine preoperative factors predictive of improvement in MR.

METHODS

Using an institutional databank of prospectively collected data, all patients undergoing isolated AVR for aortic stenosis with moderate (2+) to moderate-severe (3+) MR between 1994 and 1996 at the Montreal Heart Institute were evaluated.

RESULTS

Eighty patients with preoperative and postoperative transthoracic echocardiographic follow-up were identified. Preoperative MR was moderate (2+) in 78 patients (97.5%) and moderate-severe (3+) in 2 patients (2.5%). Mitral regurgitation was classified as rheumatic (32%), ischemic (32%), functional (21%), and myxomatous (15%). At 1-year follow-up transthoracic echocardiography, MR improved by 1 or 2 grades in 29 patients (35%), was unchanged in 44 (55%), and worsened in 7 (10%). On multivariate analysis, isolated ischemic and functional MR were the only preoperative factors predictive of MR improvement after AVR (p = 0.01): 54% of ischemic and 44% of functional MR patients showed improvement in MR after AVR compared with 23% of rheumatic and 17% of myxomatous MR patients.

CONCLUSIONS

Etiology of MR was a significant prognostic factor for improvement in MR grade. Since there was little improvement in the rheumatoid and myxomatous group, replacement or repair should strongly be considered. For functional and ischemic mitral regurgitation, a surgical correction should be performed on an individual basis.

Successful explantation of a left ventricular assist device following acute fulminant myocarditis

A left ventricular (LV) assist device was implanted in a 53-year-old woman in cardiogenic shock secondary to fulminant myocarditis. LV function recovered to normal after one week of support from an LV assist device. The device was explanted and the patient is showing a good outcome with a normalized LV function.

Incidence and prognosis of cancer following heart transplantation using RATG induction therapy

Cancer limits survival following heart transplantation. The study's objectives were to evaluate the incidence and risk factors for cancers after heart transplantation and to assess the association between i.v. thymoglobuline induction therapy [rabbit antithymocyte immunoglobulin, (RATG)] and neoplasia. From 1982 to 2002, prospective data were gathered for 207 heart transplant recipients. Except from 1982 to 1987, all patients received a 3-day course of i.v. RATG following transplantation. Forty-three malignant neoplasms (21%) were diagnosed. The most common were: skin (42%), lung (12%), prostate (9%), genitourinary (9%) and lymphoma (5%). Mean length of follow-up after transplantation was 99 +/- 57 months. Mean survival after diagnosis was 52 +/- 44 months. Multivariate analysis showed no significant increase in the incidence of cancer with recipient age, sex, number of rejection episodes, the type of immunosuppression or the use of RATG. Patients receiving RATG developed their malignancies significantly earlier after transplantation (P =0.007) and succumbed faster after the diagnosis (P = 0.06). Cancer is a limiting event for long-term survival after heart transplantation. No individual risk factors allow predicting its development. In the present cohort, RATG does not have carcinogenic effects following transplantation, but is associated with a more precocious development of malignancies.

Aspergillus Endocarditis After Cardiac Surgery

Aspergillus species infections are an increasingly common occurrence in hospital wards. Aspergillus endocarditis constitutes one of the manifestations of the disease, which bears a poor prognosis in cardiac surgery patients. A review of the literature on fungal and Aspergillus endocarditis was undertaken. Valvular risk factors, indwelling intravenous catheters, prolonged antibiotics, malignancy, and intravenous drug use increase the risk. Clinical presentation is insidious, with embolic complications often representing the first manifestation of the disease. Blood cultures are typically negative. The mortality rate is almost 100%. Amphotericin B represents the mainstay of medical therapy with several possible adjuncts. Surgery is an essential part of therapy in Aspergillus endocarditis after cardiac surgery and should be undertaken as soon as the diagnosis is made. Aspergillus endocarditis is an ominous complication after cardiac surgery. A high suspicion index, early administration of appropriate antibiotics, and prompt surgical intervention should improve the prognosis, which remains dismal.

Effects of Crystalloid, Blood and Celsior Solutions on Porcine Coronary Endothelial Function After Heart Transplantation

BACKGROUND

Coronary endothelial dysfunction occurs early after heart transplantation and predicts the development of cardiac allograft vasculopathy. Cardioplegic solutions may cause endothelial injury. The present study aimed to assess the effects of cardioplegic solutions (crystalloid, blood and Celsior) used at the time of graft harvesting on endothelial function and intimal hyperplasia 1 month after heart transplantation.

METHODS

A porcine heterotopic heart transplantation model was used. Three experimental groups were studied: crystalloid, blood and Celsior solutions were used for induction of cardiac arrest. Epicardial coronary arteries of native and allograft hearts were studied 1 month after transplantation in organ chambers. Endothelium-dependent relaxations to serotonin, bradykinin and calcium ionophore were assessed. Coronary neointimal proliferation was evaluated using histomorphometric studies.

RESULTS

Endothelium-dependent relaxations to serotonin and to calcium ionophore were significantly decreased in all 3 experimental groups vs controls (p<0.05). Endothelium-dependent relaxations to bradykinin were significantly reduced in the crystalloid group compared with the Celsior and blood groups and controls (p<0.05). There was a significantly lower rate of severe intimal hyperplasia in the Celsior group compared to the crystalloid and blood groups (p<0.05).

CONCLUSION

Celsior cardioplegic solution represents the solution of choice in terms of preservation of endothelial function and lower incidence of severe coronary intimal hyperplasia following transplantation compared with crystalloid and blood cardioplegia solutions. These early results could translate into a reduction of the long-term incidence of cardiac allograft vasculopathy and improve graft survival.