P371 1 YEAR OUTCOME OF BICARBON AORTIC MECHANICAL VALVE IN LOW–INR REGIMEN: RESULTS FROM SURE–AVR REGISTRY

Background

The drawback of using mechanical valve is lifelong anticoagulation use, and close monitoring is required to prevent postoperative complications, including thromboembolism and anticoagulation–related bleeding. Moderate anticoagulation after mechanical heart valve replacement has been proposed to reduce these risks. The present study aimed to evaluate the safety and feasibility of reduced oral anticoagulation after Bicarbon aortic mechanical valve replacement.

Methods

SURE–AVR is a propsective, multinational registry of patients undergoing aortic valve replacement. Between July 2018 and October 2020, among subjects undergoing AVR with Bicarbon valve in the SURE–AVR registry, 108 were assigned at discharge to low–INr regimen (international normalized ratio 1.5–2.5). Mean INr at discharge was 1.8+/–0.5 and 2.2+/–0.4 at 1 year. in–hospital and post–discharge outcomes up to 1 years were collected. The mean age was 55.5 +/–10.6 years old (range 25–82). Concomitant procedures included coronary artery bypass grafting (14.6%), mitral valve procedure (3.7%) and myectomy (1.9%). The follow–up duration averaged 1 year (361.8 +/– 258 days).

Results

No bleeding events were reported in the late follow up. The low–INR regimen did not affect the thromboembolism rates, since no stroke or transient ischemic attack were reported post–operatively at each time point. No in–hospital or late deaths were reported among the 108 subjects analyzed. In the early period (<30 days), three reinterventions occurred: two because of postoperative bleeding requiring thoracotomy and one due to pericardial effusion. In the late postoperative period two reinterventions with device explant occurred (one for non–structural valve dysfunction and one for endocarditis (1.2%).

Conclusion

The results of the SURE–AVr Registry demonstrated that the proposed Lower–INR Target is safe and feasible after Bicarbon aortic mechanical valve replacement. The low–intensity anticoagulation strategy is associated with a low risk of hemorrhagic events without any increase of thromboembolic complications.

Role of Immunosuppressive Regimen on the Incidence and Characteristics of Cytomegalovirus Infection in Heart Transplantation: A Single-Center Experience With Preemptive Therapy

OBJECTIVE

This retrospective single-center report sought to evaluate the relation of immunosuppressive regimen with the incidence and characteristics of cytomegalovirus (CMV) infection from 1999 to 2003.

PATIENTS AND METHODS

Immunosuppression consisted of cyclosporine microemulsion (Neoral), azathioprine (AZA), and prednisolone associated with either thymoglobulin or ATG high-dosage induction from 1999 to 2000 (AZA, 64 patients [AZA-Thymo = 38 patients and AZA-ATG 26 patients]), or cyclosporine microemulsion (Neoral), mycophenolate mofetil (MMF), and prednisolone with low-dose thymoglobulin induction from 2001 onward (n = 52 patients). Ganciclovir preemptive therapy was guided by pp65 antigenemia monitoring without CMV prophylaxis.

RESULTS

The study groups were homogeneous with respect to major perioperative risk factors. Comparing the two AZA subgroups no difference emerged as to percentage of pp65 antigenemia-positive, preemptively treated patients reflecting CMV disease incidence and relapses. AZA-Thymo patient showed significantly shorter time to first positive pp65-antigenemia and higher viral load (AZA-Thymo vs AZA-ATG, P = .004 and P = .009). The two subgroups did not differ with regard to incidence of rejection, superinfection, and graft coronary disease. By shifting from AZA to MMF no difference emerged as to incidence and characteristics of CMV infections, but there was a significant reduction in acute rejection and superinfection (AZA vs MMF P = .001 and P = .008).

CONCLUSIONS

The distinct immunological properties of thymoglobulin versus ATG significantly altered the pattern of CMV expression. MMF with reduced-dose induction did not engender a higher CMV morbidity.

Myocardial revascularization with arterial conduits. The use of lateral costal artery

We describe the long-term results of a case of complete myocardial revascularization with arterial conduit employing also lateral costal artery (LCA). A fifty-four-year-old man underwent revascularization with the implant of right internal artery mammary (RIMA) on the second portion of the right coronary artery (RCA), of the left internal mammary (LIMA) on the left artery descendent (LAD) and of LCA on the obtuse marginal arteries. The postoperative course was uneventful and a twelve-month postoperative coronary angiography showed arterial conduits to be functioning well. LCA is another source for complete myocardial revascularization with arterial conduits.

Long-term follow-up of different models of mechanical and biological mitral prostheses

Three hundred eighty-five valve prostheses were implanted between 1974 and 1981 in patients with isolated mitral disease: 157 caged-ball valves (156 Starr-Edwards; 1 Smeloff-Cutter) (group A), 107 tilting-disc valves (44 Bjork-Shiley, 49 Sorin, 14 Lillehei-Kaster) (group B), 121 porcine bioprostheses (45 Carpentier-Edwards, 66 Liotta, 10 Hancock) (group C). Perioperative mortality was 9.5% in group A, 11.2% in group B and 6.6% in group C. The follow-up was 86% complete. Actuarial freedom from complications was calculated as follows (linearised rates in brackets) in groups A, B and C, respectively: survival: 47.01% +/- 0.11 (3% patient/yr), 53.37% +/- 0.08 (1.8% patient/yr), 61.24% +/- 0.05 (2.2% patient/yr); thromboembolism: 67.94% +/- 0.09 (1.18% patient/yr); 73.07% +/- 0.06 (1% patient/yr); 97.43% +/- 0.02 (0.02% patient/yr); anticoagulation-related hemorrhage: 84.10% +/- 0.13 (0.18% patient/yr), 97.21% +/- 0.01 (0.12% patient/yr), 100%; prosthetic valve endocarditis: 100% in groups A and B, 95.76% +/- 0.02 (0.18% patient/yr) in group C; valve-related mortality: 87.52% +/- 0.03 (0.75% patient/yr), 87.96% +/- 0.03 (0.56% patient/yr), 82.53% +/- 0.04 (0.93% patient/yr); valve failure: 81.22% +/- 0.07 (0.56% patient/yr), 63.36% +/- 0.1 (1.06% patient/yr), 14.31% +/- 0.05 (4% patient/yr); treatment failure: 78.81% +/- 0.05 (1.12% patient/yr), 76.44% +/- 0.09 (0.62% patient/yr), 80.97% +/- 0.04 (1% patient/yr); all valve-related morbidity and mortality: 40.43% +/- 0.13 (1.93% patient/yr), 57.76% +/- 0.08 (1.43% patient/yr), 14.96% +/- 0.05 (4.18% patient/yr); all valve-related morbidity and mortality at 5 years: 91.97% +/- 0.02 (7.8% patient/yr), 87.06% +/- 0.03 (3.6% patient/yr), 90.27% +/- 0.03 (2.6% patient/yr); at 10 years: 80.4% +/- 0.03 (4.6% patient/yr), 75.91% +/- 0.03 (2.6% patient/yr), 37.44% +/- 0.05 (4.18% patient/yr).(ABSTRACT TRUNCATED AT 250 WORDS)

[Infective endocarditis today; heart surgery in its treatment: how and when]

The authors report the experience of 161 surgical cases operated between 1980 and 1992 because of valve endocarditis. Two hundred and two surgical procedures were performed. Patients were divided into two groups: Group I (EN) considered 117 patients with endocarditis on the native valve; Group II (EP) included 64 patients with prosthetic endocarditis. In 23 patients the prosthesis was implanted for previous endocarditis on the native valve (EP1); in 41 patients the prosthesis was implanted for other valve diseases (EP2). Each group was described according to sex, age, site of endocarditis, previous cardiac diseases, socio-economical level, hemodynamic and infective conditions at surgery, etiology of endocarditis, surgical indication, pathology report, surgical procedure and results. The results were evaluated considering surgical mortality, late mortality and recurrence of endocarditis. The main risk factors were correlated to overall survival and recurrency. Hospital mortality was 7.6% in EN, 13% in EP1, 36.5% in EP2; endocarditis recurrency was 20.3% in EN, 65% in EP1, 19.2% in EP2. Sixteen patients with prosthetic endocarditis were submitted to a second reoperation with 50% mortality; 4 patients to a third reoperation with 50% mortality; 1 patient to a fourth reoperation with no mortality. Actuarial overall survival was 40.3% at 12 years in Group EN, 33.3% at 12 years in Group EP1, 73.4% at 12 years in Group EP2. Finally the Authors report the experience of 12 stentless grafts (autologous, homologous and eterologous) implanted between March 1991 and July 1994 in patients with valve or prosthetic endocarditis with no recurrency at 42 months of follow-up.

[Biennial experience with aortic valve homografts prepared and preserved in our bank and implanted on the left ventricular outflow tract in adult patients]

A homograft bank was established in 1986 at the Institute of Cardiac Surgery of the Second University of Naples. Since then 163 aortic and pulmonary homografts have been collected, and mostly used for right ventricular outflow tract reconstruction (69 at our Institution and 14 at other Italian Centers). In March 1991 free aortic homografts were first implanted in the left ventricular outflow tract in adult patients with aortic valve and/or root disease, for a total of 15 implantations with a follow-up ranging between 3 and 19 months (mean 10 months). According to the literature and our data, operative mortality for such procedure is not higher than for ordinary aortic valve replacement. With regard to mid-term failure rate and complications, homografts are to be preferred as they don't require anticoagulation. Moreover the best indication to free homograft implantation is active aortic valve endocarditis, especially when annular abscesses are present. Reinfection rate is lesser in these patients compared to those with mechanical or bioprosthetic valves because homografts have no prosthetic material, allow exclusion of abscessual cavities from blood flow and do not require the fixation of a rigid prosthetic sewing ring in an infected, friable annulus. Finally short and mid-term haemodynamic evaluations of such patients are excellent for all the aforementioned reasons as well as for the homograft non obstruction rate.

Short-term results of bovine internal mammary artery use in cardiovascular surgery

Over a 14-month period, 28 bovine internal mammary arteries (Bioflow, Bio-Vascular, Inc.; St. Paul, Minnesota, USA) were implanted in 20 patients at our institutions. In 8 patients, the bovine internal mammary artery was used to bypass coronary vessels: in 4 of these patients, coronary artery bypass grafting was performed because of coronary disease (1 type-I aortic dissection); in the other 4 (all with aortic dissection), the modified Bentall technique was used for coronary artery reimplantation. In the remaining 12 patients, the bovine artery was used in vascular surgery: as a graft for lower-extremity occlusive disease (4 patients), arteriovenous fistula (2 patients), and aorticorenal bypass (1 patient); and as a patch to the carotid bifurcation or the common femoral artery in association with endarterectomy (5 patients). The 21 bovine grafts were all 5 mm in diameter; the 7 bovine patches were 4 mm. Of the 8 coronary bypass patients, 2 who underwent coronary artery bypass grafting had acute postoperative myocardial infarctions, and 2 who underwent the modified Bentall technique died in surgery. Follow-up angiography showed complete bovine internal mammary artery graft occlusion in 2 patients; 2 symptom-free patients refused examination. Of the vascular surgery patients, 1 with mild left leg claudication had graft occlusion, shown by angiography, 4 months after surgery. Renal scintigraphy performed in the patient with aorticorenal bypass 4 months after operation showed no blood flow to the kidney. Two patients died for reasons unrelated to bovine mammary artery grafting. The remaining patients are well and free of complications. In view of the high incidence of early occlusion, we do not recommend use of the bovine internal mammary artery graft in coronary surgery. In vascular surgery, the results are more encouraging; however, studies comprising a larger number of patients and longer follow-up are needed to determine whether the use of the bovine internal mammary artery graft can be recommended.

[Etiology and incidence of pure mitral insufficiency: a morphological study of 926 native valves]

From July 1981 to October 1988, 1597 native valves, 926 (58%) mitral and 671 (42%) aortic, were excised. The gross and histological features of all valves were studied using routine histochemical, immunohistochemical and electron microscopy techniques. As far as mitral valve is concerned the lesions were: stenosis 263 (28.6%), stenosis + incompetence 537 (57.8%) and incompetence 126 (13.6%). Our study was limited to the valves of patients undergoing mitral valve replacement because of pure incompetence. The pathological alterations of the valves were: floppy mitral valve (FMV) 59 (46.8%), rheumatic disease (RD) 50 (39.6%), infective endocarditis (IE) 13 (10.3%), papillary muscles ischemic disease (PMID) 4 (3.1%). In the FMV group the associated lesions were: aortic valve incompetence due to floppy aortic valve and noninflammatory aortic root disease (9-15.2%), tricuspid valve incompetence (4-7.8%) and atrial septal defect (7-13.7%). The commonest complication in this group was rupture of chordae tendineae requiring urgent surgery. In the RD group there was a high incidence of active rheumatism, valvulitis and papillary muscles myocarditis (37-74%) despite the laboratory data were within normal ranges. In the IE group there was an associated aortic endocarditis in 7 patients (53.8%). The FMV was the commonest cause of pure incompetence in patients who had mitral valve replacement. Rheumatic pure mitral incompetence was always associated in our experience to signs of active rheumatic disease.

Intermediate and late follow-up of the use of apico-aortic conduits in the surgical treatment of hypertrophic cardiomyopathy

Between December 1977 and July 1983, four apico-aortic prosthetic valved conduits were implanted in four patients affected by severe hypertrophic cardiomyopathy. The disease was isolated in two cases, associated with critical stenosis of the right coronary artery in one case and with a subaortic tunnel plus aortic valve regurgitation in the final case. Three patients were male and one female; the ages ranged from 6 to 49 years. All patients survived surgery and were followed-up. At present, all are living and have no postoperative symptoms. The left ventricular-aortic gradient was relieved in all cases. Echocardiographic studies during the follow-up showed an enlargement of the left ventricular cavity with a satisfactory cardiac contraction. Three years following surgery the female patient gave birth to a normal male baby. Her pregnancy was normal and without complications. Seven years after surgery the first patient was successfully reoperated because of conduit thrombosis caused by degeneration of the biological porcine valve. In the follow-up, which ranges from 18 months to 7 years (mean 4.5 years) all patients are in Functional Class I. All preoperative symptoms have been relieved for all patients and there has been no incidence of late or sudden death.

Prosthetic creation of a double outlet left ventricle: clinical experience of five cases

Five clinical cases were treated with the implantation of an apical-aortic conduit. Two adult patients were affected by obstructive myocardiopathy associated to subaortic membrane in one case, and three children by different forms of aortic stenosis (subaortic tunnel in one case; subaortic tunnel associated to severe coartation of the thoracic aorta in one case; aortic annulus hypoplasia in one case). A double outlet left ventricle has been created in all cases by implanting a composite prosthesis between the apex by implanting a composite prosthesis between the apex of the left ventricle and the aorta. The extracardiac conduit consisted of an apical curved connector and a valved dacron tubular prosthesis. The site of implantation was the supraceliac abdominal aorta in three cases and the ascending aorta in two cases. All patients survived the operation and one late mortality was observed for cerebral bleeding. The surviving patients have been restudied with satisfactory data.