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M Morea

Publications and source records attributed to M Morea.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Is coronary angioplasty less costly than aortocoronary bypass?].

We retrospectively compared the cost-benefit ratio of coronary bypass grafting (CABG) and percutaneous coronary angioplasty (PTCA). Data were obtained on 40 CABG's and 40 PTCA's patients treated from 15/2/86 to 15/9/86. All patients had at last 1-year follow-up. PTCA and CABG groups had similar baseline clinical and angiographic criteria. We analyzed the following cost components: real estate, biomedical products, drugs, hospital charges, medical fees, cardiac and non-cardiac tests. Total cost of CABG exceeds that of PTCA by a factor of 1.64: 15,095,000 vs 9,201,346 Italian liras (ILit). Taking into account early and late medical and surgical complications, the factor decreases to 1.39: 15,746,500 vs 11,323,000 ILit. After 1 year of follow-up the factor decreases to 1.18: 16,613,500 vs 14,027,500 ILit. Our data show that the initial savings were reduced when complications and follow-up are considered, but PTCA's patients had shorter hospitalization, earlier return to work, lower psychosocial stress.

Angioplasty, Balloon, Coronary↗
PubMed1990

Reoperations on heart valve prostheses: an analysis of operative risks and late results.

To evaluate risks and complications of reoperations on heart valve prostheses, we reviewed data on 183 patients who underwent reoperation because of prosthetic valve malfunction. The incremental effect of the redo procedure on hospital mortality and morbidity was studied by comparing primary and reoperative procedures and analyzing a series of possible predisposing factors. Late survival after first and second reoperations was computed, and possible determinants of late mortality were examined. Overall operative mortality was 8.7%; emergency operation (p = 0.0001), previous thromboembolism (p = 0.05), and advanced New York Heart Association functional class (p = 0.031) were the independent determinants. In a series of 1,355 patients having primary or secondary isolated valve replacement, the redo procedure was a significant risk factor in the univariate analysis (p = 0.025) but not in the multivariate analysis except for the subset of patients having mitral valve replacement (p = 0.052). The postoperative course was quite complicated, as evidenced by the long mean stay in the intensive care unit (mean stay, 3.8 days; longer than 2 days for 26% of the survivors). Nevertheless, postoperative complications were not significantly greater after a redo procedure than after a primary operation. Actuarial survival at 7 years was 57.3% +/- 8%. A comparison with a nonhomogeneous series from our institution did not demonstrate significant differences. In the subset of 16 patients having a second reoperation, late survival was 37.8% +/- 16% at 2 years. Advanced New York Heart Association class (p = 0.0001), double prosthetic valve dysfunction (p = 0.003), and any indication other than primary tissue failure (p = 0.06) were determinants of late mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Bioprosthesis↗
PubMed1990

Morphological comparison of primary tissue failure (PTF) in porcine mitral and aortic bioprostheses in the same patient.

Clinical and pathological studies have not clearly demonstrated whether primary tissue failure (PTF) in porcine bioprostheses occurs more often in the mitral than in the aortic position. We have studied morphological alterations in both positions in the same individual in 15 patients (14 mitroaortic and 1 mitroaortotricuspid) reoperated upon for PTF. Bioprostheses explanted were photographed, radiographed and observed in transmitted polarizing light. All lesions received a score on the basis of morphological criteria. The creep of the stent was measured. Calcification was slightly heavier and the degree of creep was significantly greater in the mitral position. Tears, infiltration and pannus growth did not differ between the two positions. According to our study, there is no conclusive demonstration that bioprostheses degenerate earlier and more extensively in the mitral than in the aortic position.

Adult↗
PubMed1990

In vitro evaluation of left ventricular assistance by cannulation of both femoral arteries.

The possibility of achieving effective mechanical ventricular assistance without the need for thoracotomy provides great clinical advantages. Two in vitro systems were used to assess left ventricular unloading by means of a small-diameter cannula inserted retrograde into the left ventricle by cannulation of the femoral artery. This cannula is connected to the inlet of a centrifugal blood pump (CP) that delivers the blood into the contralateral femoral artery. Steady-flow test circulation was used to pump fluid in a closed loop from a reservoir through the test cannula back into the reservoir. Pressure drops over cannulae with inner diameters of 4, 5, 6, 7, and 8 mm at flows of 2, 2.5, 3 L/min, against a pressure of 60, 80, 100, and 120 mmHg were calculated. A stationary pressure drop of 120 mmHg was measured at a flow of 3 L/min through a 100 cm cannula with an inner diameter of 6 mm. The second system was a pulsatile mock circulation composed of an atrial and an arterial reservoir linked by a pneumatic prosthetic ventricle. This system was coupled with a 100 cm cannula, 6.1 mm inner diameter, which was passed across the outflow valve of the pulsatile prosthetic ventricle and connected to a CP. Fluid was withdrawn from the ventricle and pumped back into the arterial reservoir. Pulsatile pressure drop over the cannula was measured at different CP flows for increasing systolic ventricular pressure; heart unloading was quantified as a function of CP flow under baseline and failing conditions of the prosthetic left ventricle model. At a constant CP flow the pressure drop over the cannula increased with the pulsatility inside the ventricle. The work of the prosthetic ventricle was reduced by more than 50% when the CP pump was set to 3 L/min; at the same flow setting, when the situation of a failing left ventricle was simulated, the CP was able to take over all the work of the prosthetic ventricle, establishing a stationary flow and a 25% higher mean aortic pressure. This approach to left ventricular assistance may have significant clinical relevance.

Assisted Circulation↗
PubMed1989

The Omni design: evolution of a valve.

The Lillehei-Kaster prosthesis has been the subject of an engineering evolution to close the gap between engineering expectations and clinical performance. Advanced engineering development in response to users has narrowed this gap with the Omni design (Omniscience titanium and omnicarbon Pyrolite cages). Our studies on mitral Omniscience valves demonstrated that because anatomic and surgical variations, the anterior orientation was more forgiving than the posterior orientation, resulting in lower thrombotic complications (0.5% versus 3.3% patient-year). A subsequent thicker cuff was used to reduce the probability of anatomic interference and incomplete opening after cardiac recovery. Such findings were also incorporated in the Omnicarbon design. Five European centers implanted 354 patients (198 atrial valve replacement, 115 mitral valve replacement, and 41 double valve replacement with Omniscience valves between August 1984 and January 1986. No restrictive patient selection criteria were used. As of June 1987, 96% of the patients at risk were accounted for. Average follow-up was 1.7 +/- 0.4 years (range, 0.3 to 2.8 years), with a total follow-up of 555 years. There were no cases of structural failure or clinically significant hemolysis. Ninety-one percent of the patients improved one or more functional classes. Actuarial analysis of survival probability at 3 years is 92.5% for atrial valve replacement, 97.9% for mitral valve replacement, and 93.6% overall. There were no late deaths from valve thrombosis or thromboembolism. The actuarial freedom from all thromboembolic events (valve thrombosis, thromboembolism, and transient ischemia) is 97.8% at 2 1/2 years. Through close rapport between user surgeons and designers, the evolution of a valve with improved performance becomes a reality.

Actuarial Analysis↗
PubMed1988

Protection of the heart by nifedipine cardioplegia during coronary artery surgery. A clinical-haemodynamic evaluation.

This study was undertaken to evaluate the myocardial preservation obtained by adding a Ca++ channel blocker, nifedipine, to cold potassium cardioplegia (4 mcg/Kg/L) in 24 patients undergoing coronary artery surgery. They were randomly divided into a treated (N) and a control (C) group. Significant differences between the two groups were noted in the cardiac arrest time (p less than 0.001), in the mechanical recovery mode (p less than 0.01) and in the inotropic support needed (p less than 0.01). Cardiac index increased significantly in group N but decreased in group C (p less than 0.01). Peripheral delta P/delta t and endocardial viability ratio (EVR) decreased in both groups. Coronary sinus and serum CK and CK-MB release were significantly lower in the treated group. ECG ischaemic changes occurred in 8 patients in group C but only in 1 case in group N (p less than 0.001). Arrhythmias occurred in 3 cases in group C (p less than 0.05). The incidence of perioperative myocardial infarction was not significant (2 cases in group C). These data suggest that nifedipine can protect the myocardial cell from ischaemic injury without depressing myocardial contractility or AV conduction.

Arrhythmias, Cardiac↗
PubMed1988

Fixed subaortic stenosis. Natural history of patients with mild obstruction and follow-up of operated patients.

Fifty-five patients, 37 men and 18 women, aged 8 to 71 years (median 23) with a diagnosis of fixed subaortic stenosis were seen in our institution between January 1966 and December 1983. Their subvalvular gradient varied between 0 and 135 mmHg. Aortic regurgitation was present in 44 patients. Thirty-eight patients were operated on. Sixteen patients had some additional cardiac disease, either congenital, or acquired. There were 2 early and 2 late deaths. Fifteen patients were studied again after surgery: the average peak-to-peak gradient has decreased from 88 +/- 28 to 19 +/- 16 mmHg and is zero in 5. No patient has needed a reoperation, so far. Of the 17 non-operated patients, 13 had a gradient of less than 50 mmHg; they are all in Class I-II after 1-5 years. The gradient has increased to 70 mmHg in 1 of the 4 recatheterised cases. Four patients have died, 2 suddenly, 2 of congestive heart failure. They all had a gradient of 55 mmHg or more. In conclusion, in asymptomatic patients of a somewhat "older" age, with a high prevalence of a discrete form of subaortic stenosis, an operation can be deferred if the pressure gradient is less than 50 mmHg, and there are no associated lesions. Identification of patients running the risk of sudden death remains elusive.

Adolescent↗
PubMed1988

[Results of coronary artery bypass surgery. Surgical mortality, survival and follow-up functional state. Multivariate discriminant analysis of relative risk factors].

Clinical results of coronary artery bypass surgery, have been evaluated by analyzing operative mortality, late survival, late functional results and their related risk factors. Four hundred and thirty-seven consecutive patients who underwent coronary artery bypass surgery between January, 1979, and December, 1983, were the clinical material of this study. The gender of patients was male in 89% of the cases; age ranged from 34 to 78 years with a mean of 54.8 +/- 8.2 (SD). Patients with combined surgical procedures were excluded. Follow-up averaged 55.7 months; 404 survivors have been contacted (97% of the total study population, if operative and late deaths are added); 218 patients underwent a control exercise test; postoperative employment status was determined for 242 individuals. The operative mortality was 5.49% (24 patients). Death was due to cardiac causes in 75% of the cases. The overall actuarial survival rate was 85 +/- 1.9% after 5 years and 83.4 +/- 2.2% after 7 years. When non-cardiac related deaths were excluded the actuarial rates were 88 +/- 1.7% and 87.2 +/- 1.9% after 5 and 7 years respectively. Actuarial freedom from all ischemic events (cardiac related death, late myocardial infarction or recurrence of angina) was 66.1 after five years, and was 70.2% if operative deaths were excluded. Actuarial freedom from recurrence of angina for patients alive at follow-up was 78.7% after five years, actuarial freedom from myocardial infarction was 93.5%. The mortality hazard showed a diphasic response, being higher perioperatively and constant in the following 5 years of follow-up. All ischemic events, both singularly and together, showed an accelerated rate of occurrence at the first and after the fifth postoperative year, the slope of the curve being quite flat during the 1 to 5 year interval. The control exercise test was negative for 62.8% of the patients, positive for 33.5% and undeterminable in 3.7%. Employment status was postoperatively unaffected in 49.6% of the cases, while 27.3% of the patients retired: the remaining individuals had already retired before surgery. Statistical analysis (stepwise logistic regression) identified age (p = 0.002) and cross-clamp time (p = 0.016) as significant risk factors of operative mortality. The ejection fraction showed a value close to statistical significance (p = 0.06).(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗
PubMed1987

Major sternal wound infection after open-heart surgery: a multivariate analysis of risk factors in 2,579 consecutive operative procedures.

From January, 1979, to December, 1984, at the Cardiac Surgery Department of the University of Torino Medical School, major sternal wound infections developed in 48 (1.86%) of 2,579 consecutive patients. These patients underwent open-heart procedures through a midline sternotomy and survived long enough for infection to appear. Possible risk factors were evaluated by means of a multivariate analysis. For the group of patients, we considered age, sex, hospital environment (different locations of our surgical facilities over the years), interval between hospital admission and operation, antibiotic prophylaxis, type of surgical procedure, elective or emergency surgical procedure, reoperation, duration of surgical procedures, duration of cardiopulmonary bypass, amount of blood transfused, postoperative blood loss, chest reexploration, rewiring of a sterile sternal dehiscence, duration of mechanical ventilation, and days of treatment in the intensive care unit. Univariate analysis indicated that age, sex, type and mode of surgical procedure, antibiotic prophylaxis, and duration of mechanical ventilation were not significantly associated with wound infection. For all other predisposing factors, a p value of less than .05 was demonstrated. These variables were entered in a multiple stepwise logistic regression. Six emerged as significant: hospital environment (p = .0001), interval between admission and surgery (p = .041), reoperation (p less than .0001), blood transfusions (p = .031), early chest reexploration (p less than .0001), and sternal rewiring (p less than .0001). Contamination of patients may occur before, during, and after operation, and any kind of reintervention may predispose to wound infection.

Cardiac Surgical Procedures↗
PubMed1987

Long term results (15-30 years) of surgical repair of aortic coarctation.

The late outcome in 226 patients who survived surgical repair of aortic coarctation was assessed 15-30 years after operation. Twenty six patients died during the follow up mainly from causes related to surgical repair or to associated cardiovascular anomalies. The survival rates of patients operated on between the ages of four and 20 years are 97%, 97%, 92% at 10, 20, and 30 years after operation. For patients operated on after the age of 20 the corresponding rates are 93%, 85%, and 68%. This difference is statistically significant from the fifteenth year of follow up onwards. The survival of patients operated on before the age of 20 is not significantly different from that of a comparable general Italian population. Recoarctation occurred in only 8% of patients who had end to end anastomosis, whereas it occurred in 35% of those who had other types of operation. Two thirds of the patients were hypertensive at the last visit. The actuarial curve shows that blood pressure was normal in most patients 5-10 years after operation, but 30 years after coarctation repair only 32% of patients are expected to be normotensive. Thus early repair of aortic coarctation appears to improve long term survival. Intervention in older patients and when blood pressure is high seem to be the most important predictors of late hypertension.

Adolescent↗
PubMed1986

Myocardial protection by perioperative diltiazem drip: a clinical evaluation.

This study was undertaken to evaluate the potential role of a perioperative calcium-channel blocker (Diltiazem) infusion in improving myocardial preservation. Forty consecutive CAD patients were randomly assigned to a control (C; n = 20) and a treated (D; n = 20) group. In patients in the latter group diltiazem was continuously infused at 0.5 to 2.0 mcg/kg/min i.v. from anesthesia induction until the aortic cross-clamping, and from myocardial reperfusion till the 48th postoperative hour. During the preCPB phase hypertension occurred less frequently in group D (3 vs 12 cases, p = 0.0033). In the immediate postischemic period, depression of contractility and the need for inotropic support were observed in 3 cases in group D and in 9 in group C (p = 0.0384). Postoperatively, group D patients had a lower incidence rate of hyperkinetic arrhythmias or conduction disturbances (p = 0.0218), as well as of ECG signs of ischemia (p = 0.0016). Significant CK enzyme level increase was noted in 13 patients in group C versus 4 in group D (p = 0.0040). Two perioperative myocardial infarctions were diagnosed, both in group C. These clinical data show that continuous perioperative infusion of diltiazem can effectively increase myocardial preservation during ischemic arrest, without unfavorable effects on the hemodynamics, electrical activity or mechanical performance of the heart.

Benzazepines↗
PubMed1986

Carpentier-Edwards bioprosthesis: a 7-year follow-up in 361 patients.

Three hundred sixty-one patients undergoing heart valve replacement with Carpentier-Edwards bioprostheses (CE) were evaluated: 169 patients underwent replacement of the mitral valve (MVR), 124 of the aortic valve (AVR), one of the tricuspid valve (TVR) and 67 of 2 or more valves (mVR). A total of 420 CEs were implanted. Overall operative mortality was 4.7% (7.1 for MVR, 1.6 for AVR, 4.5 for mVR). Early complications included hemorrhage (5 cases), thromboembolism (one case), paraprosthetic leak (one case). Actuarial survival rates at 5 years were computed for overall deaths, cardiac deaths and prosthetic deaths. In the 3 subgroups these 3 rates were respectively 78.7 +/- 5.6%, 82.9 +/- 5.4%, 96.4 +/- 1.6% for MVR, 88.9 +/- 3.3%, 94.2 +/- 2.3%, 98.7 +/- 1.3% for AVR, and 82.3 +/- 5.9%, 88.3 +/- 5.1%, 98.5 +/- 1.5% for mVR. Actuarial freedom from prosthetic complications at 7 years was 59.6 +/- 7.5%, 78.1 +/- 4.1% and 61.9 +/- 8.0% for MVR, AVR and mVR patients. Thromboembolism-free rates were 87.2 +/- 3.9% and 99.2 +/- 0.8% for MVR and AVR, while the thromboembolic linearized rate was 2.8% per patient-year and instantaneous risk of thromboembolism was 4.1% at one and instantaneous risk of thromboembolism was 4.1% at one year for MVR. Anticoagulant-related hemorrhage linearized occurrence was 1.0%, 1.2% and 0.8% per patient-year among the 3 subgroups. Prosthetic endocarditis occurred in 12 patients with a linearized rate of 1.1% per patient-year. Eleven of these patients were treated successfully. Three episodes of primary tissue failure were recorded (0.2% linearized rate per year, instantaneous risk 3.5% at the sixth year).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1986

Effect of platelet-activating factor (PAF) on human cardiac muscle.

The effect of platelet activating factor (PAF) on three mechanical [maximal mechanical tension (Pmax); time to peak tension; maximal rate of rise of tension (+dP/dt)] and four electrical [action potential duration (APD); resting membrane potential; overshoot; maximum rate of depolarization] parameters of cardiac function was studied on fragments of isolated human cardiac papillary muscle. 20 specimens of small tissue fragments excised from the left ventricle by open heart surgery were challenged with various doses of synthetic PAF (10(-10)-10(-6) M). PAF, but not its biologically inactive 2-lyso-derivative (lyso-PAF), induced a biphasic dose-dependent effect, characterized by a transient positive effect on inotropism (increased Pmax, +dP/dt) and of APD, followed by a marked, prolonged negative effect on both inotropism (decreased Pmax, time to peak tension, +dP/dt) and APD. No changes in resting membrane potential, overshoot and maximum rate of depolarization were detected after PAF challenge. Propranolol (2 X 10(-7) M) completely prevented the positive inotropic effect suggesting a stimulation of beta-receptors, possibly exerted by endogenous catecholamines. Indomethacin (1 X 10(-4) M) did not modify the initial positive effect, but markedly reduced the subsequent negative effect induced by PAF on inotropism. These findings are consistent with the interpretation that the effect of PAF on the inotropism is related to liberation of cyclooxygenase-derived metabolites.

Action Potentials↗
PubMed1985

Porcine cardiac bioprostheses: evaluation of long-term results in 990 patients.

Clinical results with porcine bioprostheses were reviewed for 990 patients who underwent heart valve replacement from January, 1974, to December, 1980. Eight hundred and seventy-four Hancock, 283 Carpentier-Edwards, and 10 Liotta bioprostheses were used. In 23 patients, 26 mechanical prostheses were implanted as well. Overall operative mortality was 60 out of 990 (6.06%): 30 out of 506 (5.9%) for mitral valve replacement (MVR), 13 out of 287 (4.5%) for aortic valve replacement (AVR), 1 out of 4 (25%) for tricuspid valve replacement, 0 out of 2 for pulmonary valve replacement, and 16 out of 191 (8.4%) for multiple valve replacement. Cumulative follow-up covered 1,793 patient-years. (Actuarial survival at 7 years was 76.6 +/- 3% for MVR. At 6 years, it was 83.2 +/- 2.8% for AVR and 55 +/- 13.5% for multiple valve replacement.) Prosthesis-related survival at 7 years was 91.7 +/- 1.9% for MVR, and at 6 years, it was 96.6 +/- 1.5% for AVR and 95.1 +/- 2.2% for multiple valve replacement. Bioprosthesis survival, considering deaths or complications that led to reoperation as final events, was 84.2 +/- 3.7% at 7 years for mitral valves and 87.7 +/- 3.8% at 6 years for aortic valves. Emboli per 100 patient-years numbered 3.2 for MVR, 0.5 for AVR, and 1.6 for multiple valve replacement. Twenty-seven patients underwent reoperation, 12 for perivalvular leak, 5 for endocarditis, 6 for valve thrombosis, and 4 for primary tissue failure (linearized rates of 0.7, 0.3, 0.3, and 0.2% per patient-year, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Postoperative histological diagnosis in two cases of unsuspected bioprosthetic endocarditis.

Two cases of preoperatively unsuspected porcine bioprosthetic endocarditis are presented. Both cases, thought to be a sterile thrombosis and a primary tissue failure respectively, were correctly diagnosed only with histological examination. Cultures and histological examination of the explanted tissue are necessary for a definite diagnosis in every case of prosthetic malfunction.

Adult↗
PubMed1984

Endocarditis in patients with bioprostheses: pathology and clinical correlations.

We studied 13 porcine bioprostheses removed from patients with endocarditis at our institute during the last 4.5 years. All bioprostheses had been removed at reoperation and were analyzed using anatomical and histological techniques. Each bioprosthesis was found to have developed rather constant lesions which were not related to the type of bioprosthesis. The stage of infection was not related to the duration of implantation. The presence of perivalvular abscesses was an ominous finding, often being the seat of persistent endocarditis. Our good clinical results of reoperation lead us to suggest that this be performed early once valvular or prosthetic malfunction is detected. Bioprostheses are, in our experience, the best choice in the surgical treatment of prosthetic valve endocarditis.

Adult↗