Alessandro Pellegrini

Incorrect echocardiographic diagnosis in patients with mechanical prosthetic valve dysfunction : Correlation with surgical findings

PURPOSE To identify the rate of occurrence and type of incorrect echocardiographic diagnoses in patients with mechanical valve prostheses. PATIENTS AND METHODS We studied 170 consecutive patients (73 women and 97 men) with a total of 208 prostheses who underwent surgery for mitral (n = 136) or aortic (n = 72) valve dysfunction between January 1991 and December 1997. Preoperative echocardiographic data were compared with surgical findings. Any major discrepancy between the echocardiographic reports and surgery was judged to be unconfirmed when the preoperative echocardiographic diagnosis was not confirmed at surgery, but the prosthesis was found to be dysfunctioning; and was judged to be erroneous when the preoperative echocardiographic diagnosis was not confirmed, and surgical inspection failed to reveal any other prosthetic abnormality. RESULTS There were 25 (12%) diagnostic errors. Of the 136 mitral prostheses, there were 9 unconfirmed diagnoses of paravalvular regurgitation (6 had a fibrous tissue overgrowth, 1 had a thrombus with fibrous tissue overgrowth, 1 had endocarditis vegetations, and 1 had a ball variance) and 5 erroneous diagnoses. Eleven diagnostic errors were made in the 72 aortic prostheses: there were 9 unconfirmed diagnoses (paravalvular regurgitation was diagnosed as transvalvular in 7, and transvalvular regurgitation as paravalvular in 2 cases), and 2 erroneous diagnoses. CONCLUSIONS Although echocardiography has gained great credibility among clinicians, special care should be taken when assessing patients in whom prosthetic valve dysfunction is suspected.

Prognostic indices in heart transplant candidates after the first hospitalization triggered by the need for intravenous pharmacologic circulatory support

BACKGROUND Patients with heart failure refractory to optimal oral pharmacologic therapy have a dismal short term prognosis. Heart transplantation is the only therapy shown to improve survival in these patients. Unfortunately, due to the critical shortage of donor organs, approximately 30% of listed patients with end-stage heart failure die before a suitable donor heart becomes available. The principal aim of this study was to determine whether intravenous pharmacologic circulatory support favorably influences the clinical course of heart transplant candidates or whether mechanical circulatory support should be instituted in this high risk patient population. METHODS Data from 154 consecutive hospitalizations in 125 patients 49+/-12 years were retrospectively reviewed. The product limit method was used to estimate survival. Multiple logistic regression analysis was used to identify the clinical and hemodynamic variables that independently predict outcome after each admission in which heart transplantation did not occur. RESULTS One year survival for the study population was 65%. This survival is significantly lower than the 91% 1 year survival in similarly ill patients undergoing heart transplantation. The Cox proportional hazard method identified serum bilirubin, blood urea nitrogen (BUN), serum sodium levels and right atrial pressure as independent prognostic indices. Serum bilirubin, BUN levels and duration of intravenous pharmacologic circulatory support were associated with a poor outcome. A composite index including serum bilirubin and BUN levels predicted outcome with a sensitivity and specificity of 79% and 77%, respectively. The addition of pharmacologic support duration increased the models sensitivity to 95%, but did not significantly alter specificity that was 74%. Of the 125 patients hospitalized due to the need to initiate intravenous pharmacologic support for the first time (index hospitalization), 69 (55%) were discharged after optimization of medical therapy. Of 21 patients who did not undergo transplantation during the follow-up period, 18 (86%) died within 2 years of the index hospitalization. The duration of intravenous pharmacologic support beyond which prognosis dramatically worsens without heart transplantation is 21 days. CONCLUSION Heart transplant candidates who require intravenous pharmacologic circulatory support for more than 21 days and do not receive a suitable donor heart within this period of time have a high mortality. Alternative therapies, such as implantation of a mechanical circulatory assist device should be considered in this high risk population.

Super-normal retention in hibernating myocardium: an ex-vivo study using the failing human heart

OBJECTIVE Although the relationship between delayed 201Tl distribution and blood flow in acutely ischemic and infarcted myocardium has been widely explored in the experimental setting, its behaviour in chronically hypoperfused dysfunctioning human myocardium has not yet been evaluated. METHODS In tissue samples of excised failing hearts taken from ischemic (IHD) patients and idiopathic dilated cardiomyopathy (IDC) controls, we evaluated the relationship between delayed 201Tl retention (4 h redistribution), blood flow (assessed by means of 99mTc-labelled human albumin microspheres injected during transplantation) and biochemically-assessed fibrosis. 201Tl activity was expressed as the percent of the activity in the region with highest flow and the least fibrosis. RESULTS Fibrosis and 201Tl activity were inversely related (r = -0.62, P = 0.0001). In IDC controls, low flows corresponded to uniformly preserved 201Tl retention. In IHD, 46 segments with flows < or = 0.60 ml.min-1.g-1 and 20 segments with flows > 0.60 ml.min-1.g1 showed matching delayed 201Tl retention and flow values; in the remaining 27, there was a disproportionately high tracer accumulation in comparison with flow (flow/201Tl mismatch). Despite significantly less fibrosis and lower flows, the mismatch segments showed significantly greater. 201Tl activity than the segments with concordantly high tracer retention and flow values. Conversely, at equivalent flow rates, the mismatch regions had less fibrosis than the areas with concordantly depressed 201Tl activity and perfusion. CONCLUSIONS This super-normal 201Tl retention in hibernating myocardium may indicate a mechanism of cell adaptation to chronic hypoperfusion.

Postoperative MR follow-up of type A aortic dissection.

Objective We set out to study the efficacy of MRI in the demonstration of residual alterations and postsurgical complications of type A aortic dissection. Materials and Methods From October 1988 to December 1990, 28 patients, 18 patients with type I and 10 with type II aortic dissection, underwent MR examinations for postsurgical evaluation. Features evaluated included caliber of the aorta (a) above and (b) below the prosthesis; (c) redissection; (d) persistent intimal flap; (e) presence of abdominal vessels arising from the false lumen; and (f) status of thoracic supraaortic vessels. Results Five of 28 patients were considered “normal,” due to negative results of the assessed parameters. Dilatation of the aorta was found distal to the graft in seven patients and proximal to the graft in two. Redissection was observed in 2 of 28 patients. Residual intimal flap was seen in 15 of 28 patients; the state of false lumen was well identified in 5 patients using only SE images and in 7 of the remaining 10 using phase imaging. In 25 of 28 patients, supraaortic vessels were well evaluated with involvement seen in 2 cases. In the three other patients, adequate identification was not possible. Conclusion We believe MRI is the technique of choice for monitoring the aorta after surgery in aortic dissection to identify alterations and complications and institute suitable therapy.

Correlation between extent of myocardial dysfunction and markers of irreversible damage in failing hearts

BackgroundThe structural correlates of 201Tl uptake in patients with advanced postischemic pump dysfunction are unclear. There are no good experimental models adequately reflecting the mixture of normal, dysfunctional but viable, and necrotic regions characteristic of chronic ischemic heart disease in human beings.Methods and ResultsFour heart transplant candidates with idiopathic dilated cardiomyopathy and seven with ischemic heart disease underwent rest-injection 4-hour redistribution 201Tl single-photon emission computed tomography before surgery. Delayed tracer uptake was categorized into severely reduced (<50%), mildly or moderately reduced (50% to 74%), and normal (>-75%) and related to echocardiographic wall motion and histologic findings in the hearts excised at transplantation. In idiopathic dilated cardiomyopathy, despite severe wall motion impairment, minimal or mild myocardial damage and homogeneously high 201Tl uptake were found. In ischemic heart disease, wall motion did not discriminate extensive from mild structural damage. 201Tl activity was inversely related to myocardial fibrosis (r=−0.50, p=0.0001). Severe defects in 201Tl uptake (<50%) predicted extensive (>30%) fibrosis with 83% sensitivity and 63% specificity. Segmental akinesis and apical location resulted in loss of sensitivity (74% and 58%, respectively). No histologic or wall motion abnormality accounted for poor specificity. In the individual patient, more than nine segments determined viable by imaging criteria predicted left ventricular fibrosis of less than 15% with 86% accuracy.ConclusionsThis histopathologic-clinical correlative study supports current evidence of good sensitivity but limited specificity of 201Tl rest-redistribution tomographic imaging in the evaluation of viable myocardium. In the individual patient, more than nine viable segments reliably predicted a limited extension of fibrosis.

Original articleCorrelation between extent of myocardial dysfunction and markers of irreversible damage in failing hearts

BackgroundThe structural correlates of 201Tl uptake in patients with advanced postischemic pump dysfunction are unclear. There are no good experimental models adequately reflecting the mixture of normal, dysfunctional but viable, and necrotic regions characteristic of chronic ischemic heart disease in human beings.Methods and ResultsFour heart transplant candidates with idiopathic dilated cardiomyopathy and seven with ischemic heart disease underwent rest-injection 4-hour redistribution 201Tl single-photon emission computed tomography before surgery. Delayed tracer uptake was categorized into severely reduced (<50%), mildly or moderately reduced (50% to 74%), and normal (>-75%) and related to echocardiographic wall motion and histologic findings in the hearts excised at transplantation. In idiopathic dilated cardiomyopathy, despite severe wall motion impairment, minimal or mild myocardial damage and homogeneously high 201Tl uptake were found. In ischemic heart disease, wall motion did not discriminate extensive from mild structural damage. 201Tl activity was inversely related to myocardial fibrosis (r=−0.50, p=0.0001). Severe defects in 201Tl uptake (<50%) predicted extensive (>30%) fibrosis with 83% sensitivity and 63% specificity. Segmental akinesis and apical location resulted in loss of sensitivity (74% and 58%, respectively). No histologic or wall motion abnormality accounted for poor specificity. In the individual patient, more than nine segments determined viable by imaging criteria predicted left ventricular fibrosis of less than 15% with 86% accuracy.ConclusionsThis histopathologic-clinical correlative study supports current evidence of good sensitivity but limited specificity of 201Tl rest-redistribution tomographic imaging in the evaluation of viable myocardium. In the individual patient, more than nine viable segments reliably predicted a limited extension of fibrosis.