Stefano Maffei

Myocardial vitamin E is consumed during cardiopulmonary bypass: indirect evidence of free radical generation in human ischemic heart

Although a role for free radicals in myocardial damage during cardiopulmonary bypass for open heart surgery has been postulated, direct evidence of free radical production as well as consumption of tissue antioxidants such as vitamin E is still lacking. Twenty patients (age 26-66 yr, mean 48) undergoing elective open heart surgery with moderate hypothermia, and cold crystalloid cardioplegia, were studied. Cardiopulmonary bypass time was 61.4 +/- 31.2 min. The specimens of atrial tissue collection before and after cardiopulmonary bypass, were immediately frozen in liquid nitrogen. Mean vitamin E atrial content, measured by reverse phase HPLC, was 355 +/- 249 pmol/mg of dry weight basally, 135 +/- 85 pmol/mg (p < 0.05) at the end of the ischemic period and 405 +/- 288 pmol/mg after the reperfusion period (p < 0.01). Microscopic examination of right atrial biopsies ruled out differences in fibrosis or cellular damage as the cause of vitamin E changes. Although a great basal variability in atrial vitamin E content was observed, which was independent of age, sex and clinical status, a reproducible and substantial decrease in atrial vitamin E content after cardiopulmonary bypass occurred (mean reduction 45 +/- 17% and 55 +/- 22%, respectively, after ischemia and after reperfusion). This was directly related to the aorta cross-clamping duration and partially to the minimum temperature achieved. In conclusion, apart from the great variability observed in basal vitamin E tissue content, vitamin E was always reduced during cardiopulmonary bypass, suggesting an oxidative stress on the myocardium during open heart surgery.

Familiar clustering of aortic dissection in polycystic kidney disease

Abstract The known cardiovascular manifestations in polycystic kidney include the life-threatening berry aneurysms of the cerebral circulation, as well as mitral valve prolapse, mild dilatation of the aortic root, occasional thoracic and abdominal aneurysms, and a predisposition to valvular regurgitation, which have been considered suggestive of an underlying connective tissue disorder.1,2

Early assessment of coronary reserve after bypass surgery by dipyridamole transesophageal echocardiographic stress test

The evaluation of coronary reserve within a few hours of aortocoronary bypass surgery could be of extreme utility for the follow-up or therapeutical management of these patients. In 11 men patients who underwent aortocoronary bypass surgery, a dipyridamole echocardiography stress test was carried out before (1 to 3 days), early after (68 to 130 minutes), and 1 week after surgery. The first and third tests were performed using a standard transthoracic approach, while the second was performed by a transesophageal approach. Dipyridamole was administered intravenously at a dose of 0.56 mg/kg body weight (low dose) and eventually adding 0.28 mg/kg body weight (high dose), always in the absence of antiischemic therapy. An arbitrary wall motion score (0 = eukinesia; 1 = hypokinesia; 2 = akinesia; 3 = dyskinesia) was assigned to the seven different myocardial regions in which the left ventricle was divided in order to have a semiquantitative score. Under basal conditions wall motion score per patient in the three series of tests did not change significantly (1.6, 1.4, and 1.5, respectively), while the mean score during dipyridamole administration showed significant differences (3.6, 1.9, and 1.9, respectively), indicative of the results obtained by surgical repair. The test, positive in all patients before surgery, showed wall motion abnormalities and ischemic ECG changes in two patients immediately after surgery by the transesophageal approach. One patient who had a normal basal contraction pattern and an abnormal response after the test developed in the following days a perioperative myocardial infarction, while a second patient in the follow-up period developed low-level effort angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of less than moderate residual mitral regurgitation as assessed by transesophageal echocardiography for the short-term outcomes of patients with mitral regurgitation treated with mitral valve repair

BackgroundTraditionally, in patients with mitral regurgitation (MR) a successful mitral valve repair is considered when residual MR by post-pump transesophageal echocardiography (TEE) is less than moderate or absent. Little is known about the prognostic value of less than moderate (mild or mild-to-moderate) residual MR for the early outcome of patients treated with mitral valve repair.MethodsEligible for this study were patients undergoing isolated mitral valve repair. Patients with moderate or severe residual MR after valve repair were excluded. The primary endpoint of the study was the composite of death or need of reintervention.ResultsA total of 98 patients (54 with no residual MR-Group 1, and 44 with less than moderate residual MR-Group 2) were analyzed. Of these, 72% presented with New York Heart Association (NYHA) 3/4, and 38% were women. The primary endpoint of the study occurred in 3 (5.5%) patients in Group 1 and 6 (13.6%) patients in Group 2 MR (P = 0.31). There was a trend toward a higher incidence of use of inotropic drugs post-interventional (P = 0.12), and a longer hospital stay among patients with less than moderate residual MR (P = 0.18).ConclusionIn our study population, patients with less than moderate residual MR had a trend toward a higher risk of early adverse outcomes as compared with patients with no residual MR by post-pump TEE. Studies with a larger patient population and longer follow-up data may be useful to better define the clinical significance of residual mild MR after mitral vale repair.

Preoperative assessment of coronary artery disease in aortic stenosis : A dipyridamole echocardiographic study

BACKGROUND The aim of this study was to establish the feasibility, safety, and diagnostic accuracy of the dipyridamole echocardiography test in patients with severe aortic valve stenosis for noninvasive detection of coexisting coronary artery disease. METHODS The high-dose dipyridamole echocardiography test was performed in 52 patients with severe aortic stenosis; all patients also underwent coronary angiography, independent of test results, before cardiac operation. RESULTS The dipyridamole echocardiography test was completed without major complications. One patient had transient atrial fibrillation that was reversed by aminophylline. Thirty-one patients (60%) had a negative test result; all had normal coronary arteries. Ten of the 21 patients (48%) with a positive test result had coexisting coronary artery disease. The positive predictive value of the dipyridamole echocardiography test for detection of coronary disease in patients with severe aortic stenosis was 48%. The negative predictive value was 100%. The sensitivity was 100% and the specificity was 74%. CONCLUSIONS Dipyridamole echocardiography is a safe and feasible tool in patients with severe aortic stenosis eligible for a cardiac operation. A negative test result reliably rules out a significant stenosis, whereas a positive one is much less accurate in predicting coronary artery disease.

Ambulatory follow-up of aortic dissection: comparison between computed tomography and biplane transesophageal echocardiography*

Aim of the study was to assess the relative usefulness of transesophageal echocardiography (TEE) and X-ray computed tomography (CT) in the follow-up of patients who survived an aortic dissection.Materials and Methods. We evaluated 44 patients (age = 57±12 years) with treated aortic dissection: 14 had a De Bakey type I, 20 a type II and 1 patient a type III dissection treated surgically; 1 patient had a type I, 1 a type II and 7 a type III dissection treated medically. All entered an outpatient follow-up program with serial evaluations at 1, 6 and 12 months after initial diagnosis by dual noninvasive imaging protocol. A contrast-enhanced CT scan and a TEE with biplane probe were performed on the same day and in random order.Results. A total of 252 evaluations with both CT and TEE were considered. A completely normal study was found in 45 TEE and 48 CT evaluations. The following abnormal findings could be documented by one or both techniques: thrombus in the false lumen (TEE: n=48; CT: n=45 evaluations); intimal flap (TEE and CT: n=68); aortic dilatation (TEE and CT: n=15); pericardial effusion (TEE and CT: n=3); aortic pseudoaneurysm (TEE: n=2; CT: n=3); isthmic coarctation (TEE and CT: n=1). Regarding the presence or absence of these abnormalities, which are within the diagnostic domain of both imaging techniques, the results were fully concordant in 245 studies, and discordant in 7, with an overall agreement of 97%. In addition, some abnormal findings could be detected by TEE only: aortic insufficiency (n=36); intimal tear (n=25); spontaneous echocontrast effect in the false lumen (n=39 evaluations). Other abnormal findings could be detected by CT only: a pleural effusion in 4, a truncus anonymous dissection in 1, a pseudoaneurysm due to suture dehiscence of the distal anastomosis of the ascending aorta in 1 evaluation (which yielded ambiguous results by TEE, with turbulent flow departing from the graft).Conclusion. Both CT and TEE are atraumatic, safe and accurate techniques for serial follow-up imaging of patients treated for aortic dissection. Information provided by CT is largely redundant, rather than additive, to that provided by TEE. The latter should be probably preferred for shorter imaging time, accuracy and convenience, although CT might still play a role in selected cases of ambiguous TEE results.

Cardiac Cycle-Dependent Gray-Level Variation Is Not Distorted by Abnormal Septal Motion After Cardiac Surgery: A Transesophageal Videodensitometric Study in Humans

Variation in cyclic (systolic-to-diastolic) echodensity has been demonstrated to be a reliable index of preserved myocardial function. Paradoxic septal motion can be observed frequently after cardiac surgery in the absence of any functional impairment. The aim of the study was to evaluate whether regional cycle-dependent gray-level variation in the septum is affected by abnormal septal motion after cardiac surgery. Ten patients undergoing cardiac surgery for coronary artery bypass grafting were evaluated by continuous transesophageal echocardiographic monitoring from the transgastric approach, both before and after surgery. In each patient septal motion was assessed qualitatively as normal or paradoxic. Images were digitized off-line and cyclic gray-level variation was measured in each patient by means of dedicated software. By selection, all patients exhibited normal septal motion and thickening at baseline. After surgery, five patients showed a paradoxic septal motion (group I), whereas in the remaining five patients (group II) septal motion remained normal. Percent area change, measured with the floating center-of-mass reference system, was similar in the two groups both before (I = 42% +/- 7% versus II = 44% +/- 13%; difference not significant) and after surgery (I = 39% +/- 8% versus II = 40% +/- 1%; difference not significant). Cyclic gray-level variation was also similar in the two groups, both at baseline (group I = 61% +/- 16% versus group II = 68% +/- 18%; difference not significant) and after surgery (50% +/- 13% versus 57% +/- 16%; difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

The flow-function relationship in patients with chronic coronary artery disease and reduced regional function: a Doppler transesophageal and bidimensional transthoracic echocardiography study

Background: Infra-low dose dipyridamole allows one to selectively explore myocardial viability. Transesophageal echocardiography Doppler measurement of left anterior descending coronary artery flow at baseline and following dipyridamole is an efficient tool to assess coronary flow response. Aim of this study was to determine the flow-function relationship during coronary vasodilatory stress in patients with coronary artery disease and baseline dysfunction. Methods and results: Twelve patients with resting dyssynergies and 6 controls underwent assessment of regional function and of left anterior descending blood flow velocity. Flow and function were evaluated at rest and following infra-low dose dipyridamole (0.28 mg/Kg over 4 min). Controls showed a normal function at rest and after dipyridamole. Six patients (‘Responders’) with resting dyssynergies showed an improvement in segments of left anterior descending artery territory, whereas the other six ones (‘Non-responders’) showed no functional change. Controls and ‘Responders’ had similar values of resting peak diastolic left anterior descending artery flow velocity both at rest and after dipyridamole, whereas ‘Non-responders’ showed a blunted flow response to dipyridamole. Conclusion: Myocardial segments with a resting dysfunction and a contractile reserve more often exhibit a residual flow response, whereas segments with fixed pattern show a flat flow response during coronary vasodilator stress.

Prognostic value of the dipyridamole echocardiography test performed early after aortocoronary bypass surgery.

It has been demonstrated that high dose (up to 0.84 mg/kg over 10 min) dipyridamole echocardiography stress testing is feasible even in the first few hours after coronary artery bypass graft surgery and can be used to assess the beneficial physiological effects of coronary revascularization as well as graft patency. The aim of this study was to assess the role of dipyridamole echocardiography testing performed shortly after myocardial revascularization in the stratification of prognosis during follow‐up. We studied 49 consecutive patients (45 males and 4 females; mean age 56 ± 8 years) referred to our institute for elective myocardial revascularization. Six patients had single, 14 double, and 29 triple vessel disease. Forty‐two left internal mammary artery grafts, 16 sequential venous grafts, and 45 single venous grafts were performed. All patients were submitted to dipyridamole echocardiography testing before (range 1–3 days) and shortly after (range 5–7 days) myocardial revascularization, always with the patients off antianginal medication. An arbitrary wall‐motion score grading from 0 to 3 (normal, hypokinesia, akinesia, and dyskinesia) was applied to the seven regions into which the left ventricle was divided. Before surgery 48 patients showed wall‐motion abnormalities during the test (47 patients also presented ECG changes). Angina occurred in 48 patients. One patient had ischemic ECG changes and angina. The mean wall‐motion score was 3.11 per patient before and 6.5 per patient after the test (P < 0.001). During the test performed after myocardial revascularization, two patients showed wall‐motion abnormalities, angina, and ECG ischemic changes; one patient showed wall‐motion abnormalities and angina; two patients presented only ECG ischemic changes; one patient showed wall‐motion abnormalities and angina; and two patients showed ischemic changes. The mean postsurgical wall‐motion score was 2.5 per patient before and 2.8 per patient after the test (P = NS). Of the five patients with a positive test for echocardiographic and/or ECG criteria, five suffered events during a 1‐year follow‐up (two developed Q waves and resting wall‐motion abnormalities; three had recurrence of angina); of the remaining 43 patients with a negative test for echocardiographic and ECG criteria, only two developed angina during follow‐up. The incidence of postsurgical events was 100% in patients with a positive and 5% in patients with a negative dipyridamole echocardiography test early after myocardial revascularization (P < 0.001). In conclusion, our data demonstrate that dipyridamole echocardiography stress testing is a suitable method in the early assessment of myocardial revascularization at a time when other exercise‐dependent methods are not feasible, and that a positive test in the early days after surgery indicates patients with a high risk of later developing ischemic events.

Evaluation of in vivo morphological results of balloon mitral valvotomy.

Percutaneous valvotomy is now more often considered for the treatment of mitral stenosis in poor risk patients. The aim of this study was the evaluation of the morphological changes produced by a similar procedure on the mitral valves of nine nonconsecutive patients undergoing a mitral valve replacement because of calcific isolated or prevalent mitral stenosis. The mitral valve was dilated through the left atriotomy before the valve excision with the same balloon catheter used in the percutaneous procedure. The pathological condition of the valve had been studied before dilatation by means of doppler echocardiography, cardiac catheterization and a visual examination performed by the surgeon before insertion of the balloon. At that time, the orifice area was measured with a Hegar dilator. A new measurement was performed after one or two dilatations performed at a balloon pressure of 2.7 atm. After excision, the valve was examined, photographed and X-rays were taken for evaluation of valve calcification. The pre-dilatation mean mitral valve orifice area was 1.3 +/- 0.4 cm2 and after the procedure was 2.8 +/- 0.3 cm2. In only one patient did the orifice area, originally 2.4 cm2, not increase. There was only one fused and calcified commissure, the other was normal. Before dilatation, the two commissures were fused in 17/18 cases and in 9/18, calcified. After dilatation, 5/17 commissures were completely open (not all were calcified), 10/17 incompletely opened and 2/17 remained fused (one in the above-mentioned patient).(ABSTRACT TRUNCATED AT 250 WORDS)