Left ventricular mass reduction after aortic valve replacement: homografts, stentless and stented valves.

BACKGROUND: We studied the effect of four different types of prosthetic aortic valves on time course and extent of regression of left ventricular hypertrophy after aortic valve replacement for aortic stenosis. METHODS: Four groups of 10 patients each were randomly assigned to receive: (1) aortic homograft preserved in antibiotic solution at 4 degrees C, (2) Toronto stentless porcine valve, (3) Medtronic Freestyle stentless valve, or (4) Medtronic Intact aortic valve. The left ventricular mass index, effective orifice area index, and peak and mean transaortic gradients were measured by Doppler echocardiography before the operation and 8 months postoperatively. RESULTS: The hemodynamic performance indices were much better for the homograft and stentless valves than for the stented one. The absolute left ventricular mass index reduction was greater in the homograft group compared with the Intact (p = 0.0004) and Toronto (p = 0.007) groups. The extent of percent left ventricular mass index reduction was greater only in the homograft group versus Intact group (p = 0.005). The multilinear regression analysis showed that the only predictors of a larger percentage of left ventricular mass index reduction were the homograft type, a higher valve size index, and a higher preoperative left ventricular mass index. CONCLUSIONS: When a stentless or homograft aortic valve was used instead of a stented valve to replace a stenotic aortic valve there was more complete or at least faster regression of left ventricular hypertrophy. The hemodynamic performance of stentless porcine valves was similar to that of aortic homografts, nevertheless the aortic homografts preserved in antibiotic solution offered a faster regression of left ventricular hypertrophy during the same period of time.

[Emergency coronary surgery after failed angioplasty: 11 years of experience (1987-1997)]. / Chirurgia coronarica d'emergenza dopo angioplastica fallita: undici anni d'esperienza (1987-1997).

METHODS: From January 1987 to December 1997, thirty patients underwent emergent or urgent coronary artery bypass grafting after failed elective percutaneous transluminal coronary angioplasty. Dissection/occlusion of the target artery was the commonest complication, but we also had two cases of stent dislocation and one case of coronary artery wall perforation. Two-thirds of the patients experienced extreme preoperatory hemodynamic instability (i.e., cardiac arrest or cardiogenic shock) and half had to be intubated in the Catheterization Laboratory. An average of 1.73 grafts/patient was performed. Complete coronary revascularization was achieved in 93% of the cases; the internal mammary artery could be employed in one-third only. RESULTS: In-hospital mortality was 10%, and perioperatory myocardial infarction or persistent ischemia could be detected in half of the patients. The need for aortic counterpulsation, and the use of inotropic and antiarrhythmic drugs were higher than average in this group of patients; while intensive care unit and hospital stay were longer. Patients with deteriorated preoperative hemodynamics fared significantly worse. Late results were encouraging: seventy-five per cent of all patients (and 84% of hospital survivors) were still alive an average of 52 months after surgery. Two-thirds of all patients (and 72% of hospital survivors) were alive and angina-free. CONCLUSIONS: Even in the current era, revascularization surgery after failed coronary angioplasty still carries an increased risk for postoperative complications and death, especially for patients with deteriorated preoperative hemodynamic conditions. On the other hand, postoperative middle- and long-term results are encouraging, as hospital survivors were similar to elective bypass patients regarding survival and freedom from return of angina.

[Aortic valve replacement in patients over 70: a Doppler echocardiographic study]. / La sostituzione valvolare aortica in pazienti ultrasettantenni: studio ecocardiografico Doppler.

Aortic valve disease is known to be the most frequent valvular disease in the elderly and aortic valve replacement is often the best therapeutic strategy. Hemodynamic performance of prostheses is critical in this subset of patients to ensure an optimal quality of life. Moreover, old patients with small aortic ostia are getting more and more common in clinical practice, making often necessary to implant small prostheses. If a significant pressure drop is not achieved, hypertrophy persists and left ventricular function may not improve. Such conditions have not yet been extensively studied in the elderly. The aim of this study was firstly to assess echocardiographically the performance of aortic prosthetic heart valves in old patients (> or = 70 years) and compare the results obtained in patients with prostheses of different type and size, and secondly to evaluate the postoperative changes in left ventricular hypertrophy and function in a subset of patients with isolated or prevalent aortic stenosis. One hundred fifty-one patients were initially considered; global mortality was 9.3% at 20 +/- 12 months from intervention. In the 75 patients with a postoperative echocardiogram, transprosthetic gradient was 27 +/- 12 (max) and 15.1 +/- 6.6 (mean) mmHg. Mean functional prosthetic area (FPA) was 1.5 +/- 0.5 cm2. No statistically significant differences could be demonstrated between mechanical and biological prostheses. Three groups were identified, according to prosthetic size (Group 1: diameter < 23 mm, Group 2: diameter 23 mm, Group 3: diameter > 23 mm). Among groups, max and mean gradients as well as FPA were found to be significantly different. Respectively max gradient was 33.2 +/- 13, 26 +/- 11, 20.2 +/- 7.2 mmHg (p < 0.05), mean gradient was 17.2 +/- 6.1, 15.4 +/- 7.6, 11.7 +/- 4.3 mmHg (p < 0.01) and FPA was 1.2 +/- 0.3, 1.5 +/- 0.3, 1.8 +/- 0.7 cm2 (p < 0.05 between Group 1 and Group 3). In a subgroup of 31 patients with isolated or prevalent aortic stenosis, a significant interventricular septal thickness reduction was found postoperatively (14.3 +/- 2.3 vs 12.6 +/- 8.0 mm, p < 0.001). Posterior wall thickness decreased similarly, but to a lesser extent; left ventricular diameters and myocardial mass also significantly decreased (left ventricular mass: 186 +/- 45 vs 146 +/- 38 g/m2, p < 0.001). When prosthetic size was considered, septal thickness reduction was more evident in Group 1 and Group 2 (p < 0.05 and p < 0.01). On the contrary, a significant improvement in left ventricular diameters was observed only in Group 3 (p < 0.05). Left ventricular mass decreased significantly in Group 2 and Group 3 (p < 0.01 and p < 0.05). Such improvements could be demonstrated only in those patients (79%) who showed at least a 50% reduction in the transvalvular gradient. In this subset, left ventricular function also significantly improved (fractional shortening: 29 +/- 0.7 vs 33 +/- 0.7%, p < 0.02). In conclusion, aortic valve replacement in the elderly is a safe and effective therapeutic strategy. In patients with small aortic prostheses, the transvalvular gradient was found to be slightly but significantly higher as compared to that of larger prostheses. However, left ventricular function was good and similar in all subgroups. No significant differences were found between mechanical and biological prostheses. In old patients with isolated or prevalent aortic stenosis a significant reduction in left ventricular hypertrophy and mass is observed within 2 years from intervention. An increase in myocardial contractility can also be expected, if at least a 50% reduction in transvalvular gradient is obtained.

Posttraumatic left ventricular pseudoaneurysm due to intramyocardial dissecting hematoma.

A left ventricular aneurysm can develop in patients sustaining blunt chest injury. This condition has been attributed to myocardial contusion or to a direct vascular lesion leading to myocardial necrosis. We report the case of a pseudoaneurysm resulting from myocardial dissection beginning from a small tear in the endocardial wall. Successful surgical exclusion of the pseudoaneurysm by endoaneurysmal patch closure of the communications between the aneurysm and the left ventricular cavity is described.

Left main coronary artery atresia: literature review and therapeutical considerations.

OBJECTIVE: Left main coronary artery atresia is a rare coronary anomaly in which there is no left coronary ostium, the proximal left main trunk ends blindly, blood flows from the right coronary artery to the left via small collateral arteries and retrogradely in at least one of the left-sided arteries. Since published case reports are few and rather scattered, no comprehensive information about this uncommon anomaly is available. METHODS: A through search for published cases of left main coronary atresia was performed in the major medical journals by electronic (MEDLINE and INTERNET) and hand-scanning. RESULTS: The authors found 28 cases of left main atresia (including two from their own experience), 15 of which were pediatric; five of these cases had associated cardiac anomalies. While pediatric patients were usually overtly symptomatic early in their life (syncope, dyspnea, sudden death, failure to thrive, infarction, ventricular tachycardia), adult patients began showing symptoms (angina, dyspnea, sudden death) only at an advanced age; associated coronary atherosclerosis seemed to be uncommon, though (2/13 adult patients, 15%). We know of only one asymptomatic patient, a 76-year old lady who had died of unrelated causes; in her case left main atresia was an unforeseen autopsy finding. Four untreated patients had died suddenly; most of the others were highly symptomatic and required surgical therapy, usually as direct coronary artery revascularization via one or more saphenous vein or mammary artery grafts to the left-sided arteries; all revascularized patients were reported to be alive and well; in one pediatric case the left main coronary artery was reconstructed using an aortic wall baffle, with a good result. In contrast, the outcome of patients who did not receive revascularization has been poor. CONCLUSION: In light of the favorable results obtained by surgical therapy, the authors endorse prompt coronary artery revascularization for all patients with left main coronary artery atresia.

Gabexate mesilate, a new synthetic serine protease inhibitor: a pilot clinical trial in valvular heart surgery.

OBJECTIVE: To assess the effects of gabexate mesilate ([GM], Foy, ONO Pharmaceutical Co, Osaka, Japan) on blood loss in cardiac valve replacement surgery and to establish whether GM reduces blood loss or transfusion requirements after this surgery. DESIGN: Randomized single-blind trial in 30 patients receiving either GM (2 mg/kg/h in a central venous catheter), or no GM, after heparin. SETTING: Department of Anesthesia and Intensive Care, Cardiac Surgery, in a hospital in Italy. PARTICIPANTS: Consent patients. INTERVENTIONS: Cardiac valve replacement surgery. MEASUREMENT AND MAIN RESULTS: Intraoperative and postoperative bleeding, blood transfusion, hemoglobin, and hematocrit were compared. In the GM group bleeding was reduced and no transfusions were required. CONCLUSION: GM appears to play a useful role in reducing blood loss during extracorporeal circulation in cardiac surgery.

[Psychological, behavioral and occupational status changes after an aortocoronary bypass intervention]. / Variazioni psicologiche, comportamentali e di status professionale dopo intervento di bypass aortocoronarico.

BACKGROUND. Studies on the quality of life after coronary artery by-pass grafting (CABG) have yielded discordant results. Several studies have described psychological and social improvements while others have reported a lack of change in behavioural risk factors and return to work. There have been no reports on Italian patients, and, because of the wide range of psychological measures used in previous studies, it is difficult to draw any general conclusions. The aim of this study was to assess the psychological sequelae of CABG. METHODS. A total of 164 patients (142 men and 22 women, aged 60 years) with myocardial ischemia, completed the CBA-H Questionnaire 3-5 days before elective CABG and again after 6 months. RESULTS. State anxiety scores were lower after surgery (p < .000) as were health fears (p < .000), depression (p < .009) and life stress (p < or = .000) scores. There were also improvements in well-being (p < .003), affective relationships (p < .000) and sexual relations (p < .0007). There was a decline in behavioural risk factors, namely: smoking behaviour (p < .09), alcohol consumption (p < .002), over-eating (p < .0000) and sedentary life-style (p < .02). Clinical post-operative complications did not negatively influence patients' psychological state and return to work. Preoperative health fears (p < .04) and social anxiety (p < .02) did influence patients' return to work. CONCLUSIONS. In conclusion, psychosocial function, health state and quality of the life generally improved after elective CABG. Return to work was found to be an unreliable measure of the success of surgery. Pre- and post-operative data revealed a general denial trait which identifies patients at greater risk of cardiovascular events after CABG.

[Structural and morphometric analysis of the internal mammary artery used in coronary bypass surgery]. / Analisi strutturale e morfometrica dell'arteria mammaria interna utilizzata nel bypass coronarico.

The internal mammary artery is currently regarded as the optimal canal in coronary bypass surgery. Even if the motives for the excellent behaviour of this artery are still not fully clarified, the morphological and morphofunctional study of its wall can contribute to explain the clinical results obtained using this canal. In order to complete existing studies on this topic and to increase our knowledge of the structure of this artery, segments of internal mammary artery taken from patients undergoing coronary bypass surgery were analysed. Histological, immunohistochemical, histochemical and morphometrical tests were performed in these samples. The results of the tests underline the considerable complexity of the internal mammary artery whose walls appear to be rich in elastic fibres, divided into numerous lamellar structures concentric to the vasal lumen and without vasa vasorum in the tunica media given that this is adjacent to the tunica adventitia. Moreover, the marked presence of the NO-synthase enzyme, responsible for nitrogen monoxide synthesis, was observed in the endothelial layer and tunica media, as suggested by histochemical analysis. These data argue in favour of a structure able to resist the considerable hemodynamic stress to which the artery is subjected after bypass, a structure which is functionally well adapted to receive the majority of nutrition through its own lumen, and, lastly, a structure capable of self-regulation in response to the requirements made from time to time. These findings may further our understanding of the morphofunctional aspects of the internal mammary artery and may contribute to explaining the latter's relative immunity to atherosclerosis and, thus, its success in coronary bypass.

New bileaflet bioprosthesis: early and mid term results.

A new bovine pericardial bioprosthesis (AMB bioprosthesis) with a bileaflet geometry was designed and developed, with the aim of achieving uniform stress distribution within the prosthesis. The ultimate goal was to limit tissue degeneration to a minimum by attaining optimum fluid dynamics, thereby obtaining an extended clinical durability. The two-leaflet, dome-shaped geometry with a central hinge allowed a very low profile, low ventricular projection in the mitral position, large effective orifice area and low gradients. The design of the thin Delrin stent and the centrally crossing bridge was developed using finite element analysis. Pre-clinical laboratory investigations showed very low trans-valvular gradients and no mechanical or tissue failure after 400 million cycle accelerated wear test. The final model of the prosthesis was manufactured by Baxter-Edwards CVS Division and tested in sheep with good results for up to five months. A limited clinical trial was started in January 1990 and stopped one year later encompassing 12 aortic and six mitral implants. The patients were followed clinically and by echocardiography three, six and 12 months, and four years after surgery. Mean gradients were 4 mmHg in the mitral and 10 mmHg in the aortic position with only minimum regurgitation and no tissue failure. We conclude that early and mid term results with this new pericardial bioprosthesis appear to be favorable and intend to closely monitor further outcome within the limited patient population.

[Surgical revascularization of the myocardium for atresia of the left main coronary artery and atherosclerotic coronary disease]. / Rivascolarizzazione chirurgica del miocardio per atresia del tronco comune e coronaropatia aterosclerotica.

The authors report a rare case of atresia of the left main coronary artery in an adult patient, symptomatic for effort angina. At coronarography, the left main coronary artery was not found; instead, the arteries of the left coronary tree were filled via a single collateral vessel arising from the ostium of the right coronary artery and ending in the trunk of the left anterior descending artery. All left arteries had very narrow calibres, almost hypoplastic, while the right coronary artery had a normal calibre. All the principal arteries had important stenoses. The patient underwent complete cardiac revascularization, and, sixteen months later, is free from angina. Rest and stress myocardial scintigraphy, control coronary angiography and Doppler analysis of internal mammary artery flow demonstrated normal myocardial perfusion, adequate blood flow through the grafts and good runoff in the native vessels. Hence, the authors conclude that such patients should be referred for coronary artery revascularization, since surgical results are good and the small calibre of the left coronary arteries is no contraindication.

Blood products usage in cardiac surgery.

Many patients undergo cardiac surgery with preexisting congenital and acquired coagulation defects. Almost all of these can be recognized and corrected preoperatively. In a complex operation involving the use of cardiopulmonary bypass (CPB), the significance of isolated changes in coagulation tests is difficult to assess. Many variable must be taken into consideration, including the coagulation and fibrinolytic systems, their natural inhibitors, and platelet number and function. CPB induces a variety of abnormalities of coagulation. These abnormalities do not always cause clinically significant bleeding. When they do, laboratory assessment and blood-component usage can usually correct the defect. The use of blood products is associated with allergic, viral, and hemolytic risks. Exciting advances have been made in the use of pharmacologic alternatives to blood products. Both Desmopressin (DDAVP) and aprotinin seem promising in this respect, but more investigation is needed on specific indications for these drugs and on the possible problems with a drug-induced thrombotic tendency. In the future, anesthesiologists and surgeons may look forward to more safe and effective therapy of bleeding in cardiac surgical patients.

[Doppler echocardiographic analysis of the short-term results of surgical repair of mitral valve prolapse in myxomatous degeneration]. / Valutazione ecocardiografica Doppler dei risultati a breve termine dell'intervento di riparazione di prolasso valvolare mitralico nella degenerazione mixomatosa.

Ten consecutive patients with pure mitral regurgitation due to floppy valve underwent valve repair operations. Postoperative mitral continence or regurgitation and diastolic flow across the valve were evaluated by Doppler echocardiography. Mean follow-up was 6.4 months. Four patients showed minimal and 3 mild regurgitation; no regurgitation was detected in 3. A significant peak diastolic atrioventricular gradient (10 mmHg) was observed in only one patient. All patients showed symptomatic improvement and a decrease in ventricular diameters. Repair of floppy mitral valves is feasible and gives good results. Doppler echocardiography is a useful technique for monitoring postoperative valve function.

[Average-term effects of reparative surgery of the mitral valve]. / Risultati a medio termine della chirurgia riparativa della valvola mitralica.

The paper summarizes a personal experience at Harefield Hospital in surgical repair of the mitral valve. From Oct. 1976 to June 1978 among 43 consecutive mitral valve operations 38 reparative procedures were performed. The aetiology was rheumatic in 32 cases, degenerative (floppy valve) in 4; subacute bacterial endocarditis superimposed on a rheumatic valve in 1 and congenital in 1. The mitral valve was stenotic in 21 cases, incompetent in 5 and both stenotic and incompetent in 13. One patient died, whereas two had to be reoperated. At a postoperative symptomatic evaluation (mean follow up 25 months) 25 patients (71%) are asymptomatic; 9 (26%) are improved and 1 remains unchanged.

[Results of conservative or substitutive surgical treatment in mitral valve prolapse caused by redundant cusps]. / Risultati del trattamento chirurgico conservativo o sostitutivo nel prolasso mitralico da cuspide ridondante.

Between October 1969 and October 1979 120 patients (78 males and 42 females, mean age 48 years) underwent surgical correction of floppy mitral valve at Harefield Hospital. Family history of mitral valve disease was present in 3 patients and 6 had skeletal manifestations of Marfan syndrome. The presenting symptom was shortness of breath in 110 (92%), chest pain in 18 (15%), and palpitations in 29 (24%). Thirty-two patients had more than one symptom. A history of bacterial endocarditis was obtained from 18 patients. At the time of operation 88% of the patients were in class III-IV NYHA. Forty-five patients had mitral valve replacement and the remaining 75 had a conservative procedure. Findings at operation were: rupture of posterior chordae in 72 (60%); rupture of anterior chordae in 15 (13%); rupture of anterior and posterior chordae in 6 and elongation of chordae without rupture in 27 (22%). Hospital mortality for isolated replacement was 6.5%. Twenty-seven patients (22%) died subsequently (mean follow-up of 75 months). Hospital mortality for repair was 3.2% and late mortality mean follow-up 34 months) was 6.5%. Sixty-seven patients are asymptomatic and 21 are improved. A conservative approach to floppy mitral valve disease has been adopted in all patients since 1974 and has given better early and late results compared to valve replacement.

[Long-term evaluation of aorto-coronary bypass surgery]. / Valutazione a distanza del bypass aortocoronarico.

Between October 1969 and June 1978; 878 patients underwent coronary bypass grafting at Harefield Hospital. Five hundred and fifty-four patients (63%) were restudied postoperatively by coronary angiography in order to evaluate graft patency in relation to time, runoff, influence of endoarterectomies, clinical condition, age, sex, risk factors and the progression of the disease in native vessels. Patency rate was 85% in 197 patients restudied between 1 and 6 years postoperative (mean 26 months). Patency rate of 63 endoarterectomized vessel restudied between 1 and 6 years postoperatively was 84%. Restudy of 343 patent grafts shows a good runoff in 299 (87%). The effects of runoff on long term patency were evaluated in a group of 81 patients restudied twice with mean interval of 18.3 months between the first and second investigation. Eighty-six percent of 147 grafts showed a good runoff at the second study. Age, sex and risk factors do not appear to influence long term patency rate. Two hundred and sixty out of 354 patients followed up postoperatively from 6 to 86 months (mean 28.2 months) were asymptomatic and the graft patency rate was 87%. Seventy-four of these patients had all their grafts patent. Sixteen symptomatic patients had a patency rate of 55%, thirty-seven percent of them had all the grafts patent. Progression of the disease in native vessels was observed in 23 out of 132 non grafted vessels (17%) and distal to the graft in 7 out of 252 bypassed vessels (3%).

[Myocardial revascularization combined with endoarterectomy (author's transl)]. / La rivascolarizzazione miocardica associata ad endoarterectomia.

The paper summarize a personal experience in myocardial revascularization combined with endoarterectomy for diffuse coronary artery disease. From Feb. 1977 to June 1978 at Harefield Hospital 60 patients had 138 grafts. In 32 patients, 42 endoarteriectomies were performed (30% of all grafted vessels); of these 19 (45%) were to LAD; 4 (10%) to CX and 19 (45%) to RC. The overall mortality was of 1 patient. Symptomatic evaluation shows that 26 patients (84%) are asmptomatic and 5 (16%) are improved. Restudy of 24 (32 endoarterectomies) shows a patency rate of 75%.

[The intraaortic balloon counterpulsation (author's transl)]. / La contropulsazione con pallone intra-aortico.

Indication for and clinical experience with intra aortic balloon counterpulsation at Harefield Hospital are reported. From Sept. 1973 to Sept. 1977, 87 patients had counterpulsation. Indications were: postinfarction cardiogenic shock in 28 cases; acute ischaemic episode in 19 and postoperative cardiogenic shock in 40. Of the 28 patients in postinfarction cardiogenic shock 15 underwent open heart surgery with an hospital mortality of 40%. All the patients with acute ischaemic episodes had surgery with an hospital mortality of 10%. In the group of 40 patients with postoperative cardiogenic shock overall mortality was 47%: it was of 18% in the 22 patients who had coronary artery bypass surgery while it was of 83% in the 18 patients who had valve surgery. Early recognition and treatment of conditions requiring counterpulsation is essential for achieving the best results.

[The conservative mitral valve surgery (author's transl)]. / La chirurgia conservativa della mitrale.

From 1969 to 1976 at Harefield Hospital 260 patients underwent conservative mitral valve surgery. The different techniques used are described. Of the 223 patients followed up (1 to 8 years, mean follow up 48 months) 73% are asymptomatic, 20% are improved and 7% are the same or worse. A conservative operation is possible in approximately 85% of the cases and according to our results this should be the operation of choice in mitral valve surgery.

[Primary repair of large ventricular septal defects in the first year of life (author's transl)]. / La correzione del difetto interventricolare entro il primo anno di vita.

It has been our policy at Harefield Hospital since 1971 to perform primary repair of large ventricular septal defects in the first year of life if there is severe intractable cardiac failure or persistent pulmonary hypertension in infants approaching the first year of age. Twenty-six infants underwent repair; their ages were between one and twelve months. One child died early. The remaining 25 have been followed up for between 6 and 78 months (mean 30.3 months). There have been no late deaths and all children are asymptomatic. Late, postoperative cardiac catheterization was performed in 17 patients. This showed that in all the patients the pulmonary artery pressure was normal and there were no residual shunts. It is concluded that primary repair of large ventricular septal defects in the first year of life gives good results and appears to prevent pulmonary hypertension.