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Biomedical subjects

Ottavio Alfieri

Publications and source records attributed to Ottavio Alfieri.

At least 19 recordsLinked to original sources
PubMed2005

Mitral valve repair for functional mitral regurgitation in end-stage dilated cardiomyopathy: role of the "edge-to-edge" technique.

BACKGROUND: The aim of this study was to assess the results of mitral valve (MV) repair in functional mitral regurgitation because of end-stage dilated cardiomyopathy (DCM). METHODS AND RESULTS: Seventy-seven patients with end-stage idiopathic (26 patients) or ischemic (51 patients) DCM underwent MV repair for functional mitral regurgitation (3 to 4+/4+). Fifty-eight patients (75.3%) were in New York Heart Association class III, and 19 (24.6%) were in IV. In 23 patients (29.8%) with a coaptation depth <1 cm, an isolated undersized annuloplasty was used. In the remaining 54 (70.1%), with a coaptation depth > or =1 cm, the "edge-to-edge" technique was associated with the annuloplasty. In most of the cases (88.3%), a complete rigid/semirigid ring was used. Concomitant coronary artery bypass graft was performed in 39 patients (50.6%). Hospital mortality was 3.8% (3 of 77). Actuarial survival was 90.7+/-3.64%, and freedom from cardiac events was 81.8+/-7.96% at 2.7 years. At a mean follow-up of 18.4+/-9.8 months (range, 1 month to 5 years) New York Heart Association class improved from 3.4+/-0.4 to 1.4+/-0.6 (P<0.0001). Mitral repair failure (recurrence of MR > or =3+/4+) was documented in 7 patients (9%): 2 in the edge-to-edge (2 of 54, 3.7%) and 5 in the isolated annuloplasty group (5 of 23, 21.7%) (P=0.03). Freedom from repair failure at 1.5 years was 95.0+/-3.4% and 77+/-12.1%, respectively (P=0.04). The absence of the edge-to-edge was the only predictor of repair failure (P=0.03). When residual MR was absent or mild, a reverse left ventricular remodeling was clearly documented. CONCLUSIONS: In patients with end-stage DCM, MV repair is feasible with low hospital mortality and important symptomatic improvement. The association of the edge-to-edge technique to the undersized annuloplasty can significantly improve the durability of the repair.

Adult↗
PubMed2005

An annular prosthesis for the treatment of functional mitral regurgitation: finite element model analysis of a dog bone-shaped ring prosthesis.

BACKGROUND: Undersized annuloplasty is commonly used in the treatment of functional mitral regurgitation. However, in the case of severely dilated ventricles, annuloplasty may be inadequate to counteract leaflet tethering. My colleagues and I hypothesized that modifying the shape of the annular prosthesis to account for the specific anatomy of functional mitral regurgitation could challenge extreme leaflet tethering. METHODS: Using finite element model simulations, we tested valve competence after the implantation of conventional D-shaped versus dog bone-shaped annuloplasty rings, the latter of which was designed to selectively reduce the septolateral dimension of the annulus. Three models were compared: model A, simulating the native mitral valve; model B, simulating the same valve after annuloplasty with a conventional D-shaped annuloplasty; and model C, simulating a dog-bone annuloplasty ring implantation. Each model was then challenged by progressively pulling the tip of the papillary muscles away from the annulus plane to simulate ventricular remodeling and leaflet tethering. Valve competence was compared in each model for each degree of leaflet tethering. RESULTS: After maximal leaflet tethering simulation (4-mm apical displacement of the papillary tips), the regurgitant area increase was 70.4 mm2 for model A and 52.9 mm2 for model B. In model C, the regurgitant area was only negligibly affected by papillary displacement, increasing to 3.9 mm2. CONCLUSIONS: An annular prosthesis with selective reduction in the septolateral dimension is more effective than a conventional prosthesis for treating leaflet tethering in functional mitral regurgitation. Use of disease-specific annular prostheses is needed to improve the results of valve reconstruction.

Animals↗
PubMed2005

Beat-to-beat effects of intraaortic balloon pump timing on left ventricular performance in patients with low ejection fraction.

BACKGROUND: Intraaortic balloon counterpulsation (IABP) timing errors during arrhythmia may result in afterload increases which may negatively influence left ventricular (LV) ejection and LV mechanical dyssynchrony. The aim of our study was to determine beat-to-beat effects of properly timed IABP, premature IAB inflation, and late IAB deflation on LV performance and LV mechanical dyssynchrony in heart failure patients undergoing cardiac surgery. METHODS: In 15 patients, LV pressure-volume relations and LV dyssynchrony were measured by conductance volume catheter. Properly timed IABP was evaluated at a 1:1 assist ratio within a 10 seconds time-span. Premature IAB inflation and late IAB deflation were evaluated at a 1:4 assist ratio. RESULTS: Properly timed 1:1 IABP acutely decreased LV end-systolic volume by 6.1% (p < 0.0001) and LV end-systolic pressure by 17.5% (p < 0.0001) due to decreased aortic impedance. Stroke volume (SV) increased by 14% (p < 0.0001), which correlated markedly with a decrease of LV mechanical dyssynchrony (p < 0.0001). The largest SV increases occurred in patients with lowest contractile state. Premature IAB inflation decreased SV by 20% (p < 0.0001) due to abrupt increase of LV afterload during late ejection. Late IAB deflation increased SV and stroke work by 18% (p < 0.0001) and 16% (p < 0.01) respectively, due to increased afterload during early ejection and decreased afterload during late ejection. CONCLUSIONS: Left ventricular performance during IABP is causally related to changes in LV afterload, and the timing of these changes in relation to contraction or relaxation phases, to LV mechanical dyssynchrony and to contractile state.

Humans↗
PubMed2005

Automatic intraaortic balloon pump timing using an intrabeat dicrotic notch prediction algorithm.

PURPOSE: The efficacy of intraaortic balloon counterpulsation (IABP) during arrhythmic episodes is questionable. A novel algorithm for intrabeat prediction of the dicrotic notch was used for real time IABP inflation timing control. DESCRIPTION: A windkessel model algorithm was used to calculate real-time aortic flow from aortic pressure. The dicrotic notch was predicted using a percentage of calculated peak flow. Automatic inflation timing was set at intrabeat predicted dicrotic notch and was combined with automatic IAB deflation. EVALUATION: Prophylactic IABP was applied in 27 patients with low ejection fraction (< 35%) undergoing cardiac surgery. Analysis of IABP at a 1:4 ratio revealed that IAB inflation occurred at a mean of 0.6 +/- 5 ms from the dicrotic notch. In all patients accurate automatic timing at a 1:1 assist ratio was performed. Seventeen patients had episodes of severe arrhythmia, the novel IABP inflation algorithm accurately assisted 318 of 320 arrhythmic beats at a 1:1 ratio. CONCLUSIONS: The novel real-time intrabeat IABP inflation timing algorithm performed accurately in all patients during both regular rhythms and severe arrhythmia, allowing fully automatic intrabeat IABP timing.

Aged↗
PubMed2005

Minimally invasive mitral valve repair in the context of Barlow's disease.

BACKGROUND: The aim of this study is to report our overall experience with minimally invasive mitral valve repair for correction of severe mitral regurgitation in the setting of Barlow's disease. METHODS: Between 1999 and 2003, 48 patients with bileaflet prolapse in the context of Barlow's disease underwent minimally invasive mitral valve repair using the "edge-to-edge" technique. Mean age was 37.9 +/- 9.1 and 58% were female. Most of the patients were in New York Heart Association (NYHA) class I or II and all of them had normal left ventricular ejection fraction. RESULTS: There were no conversions to sternotomy. Mean cardiopulmonary bypass and aortic cross-clamp times were 77 +/- 16 minutes and 56 +/- 8 minutes. No in-hospital deaths and no major postoperative complications occurred. At a mean follow-up of 22.7 +/- 10.6 months, survival rate and freedom from reoperation were 100%. All patients were in NYHA class I and in sinus rhythm. No residual mitral regurgitation was detected at echocardiography in 33 (68.7%) patients and mild insufficiency was found in 15 (31.2%). The degree of satisfaction in terms of cosmesis and postoperative pain was very high and 73% of the patients were back to work and to normal activity in 4 weeks. CONCLUSIONS: Mitral insufficiency due to Barlow's disease can be effectively corrected through a minimally invasive approach by using the "edge-to-edge" technique. In our opinion, the excellent midterm results and the high degree of patients satisfaction certainly justify the adoption of this strategy in a selected group of young and active people.

Adolescent↗
PubMed2005

Myocyte changes and their left atrial distribution in patients with chronic atrial fibrillation related to mitral valve disease.

It has been found that the pulmonary veins and adjacent left atrial posterior wall (LAPW) are deeply involved in both the initiation and maintenance of atrial fibrillation (AF), and the identification of these high-risk sites has aroused great interest in investigating their histopathologic substrate. We used light and conventional electron microscopy to evaluate the differential myocyte and interstitial changes in LAPW and left atrial appendage (LAA) samples from 28 patients with chronic AF undergoing mitral valve surgery and from 12 autoptic controls. There were always more myocytes with loss of sarcomeres in the LAPW than in the LAA (19.9% +/- 7.7% versus 8.2% +/- 5.0%; P < .0001), and the LAPW showed more marked immunohistochemical evidence of dedifferentiation, characterized by the reexpression of smooth muscle actin. In pathological left atria, myocyte diameter in the LAPW and LAA was comparable (19.0 +/- 1.5 versus 18.5 +/- 2.0 microm; not significant) but larger than in the controls (11.9 +/- 0.8 and 12.1 +/- 1.3 microm, respectively; P < .0001). A terminal deoxynucleotidyltransferase assay did not reveal any myocyte apoptosis. The LAPW also showed more interstitial fibrosis than the LAA (7.49% +/- 3.34% versus 2.80% +/- 1.35%; P < .0001). Ultrastructural examination confirmed the presence of myocyte myocytolysis in the perinuclear area and showed changes in mitochondrial shape. In conclusion, the LAPW in patients with chronic AF related to mitral valve disease seems to be a particular anatomical site in which major myocyte and interstitial changes are concentrated, whereas the LAA is more protected. This remodeling may increase the heterogeneity of LAPW electrical conduction, thus confirming this location as an elective target for the ablation treatment of AF.

Adult↗
PubMed2005

Acute decrease of left ventricular mechanical dyssynchrony and improvement of contractile state and energy efficiency after left ventricular restoration.

OBJECTIVE: Surgical left ventricular restoration by means of endoventricular patch aneurysmectomy in patients with postinfarction aneurysm should result in acute improved left ventricular performance by decreasing mechanical dyssynchrony and increasing energy efficiency. METHODS: Nine patients with left ventricular postinfarction aneurysm were studied intraoperatively before and after ventricular restoration with a conductance volume catheter to analyze pressure-volume relationships, energy efficiency, and mechanical dyssynchrony. The end-systolic elastance was used as a load-independent index of contractile state. Left ventricular energy efficiency was calculated from stroke work and total pressure-volume area. Segmental volume changes perpendicular to the long axis were used to calculate mechanical dyssynchrony. Statistical analysis was performed with the paired t test and least-squares linear regression. RESULTS: Endoventricular patch aneurysmectomy reduced end-diastolic volume by 37% (P < .001), with unchanged stroke volume. Systolic function improved, as derived from increased +dP/dt(max), by 42% (P < .03), peak ejection rate by 28% (P < .02), and ejection fraction by 16% (P < .0002). Early diastolic function improved, as shown by reduction of -dP/dt(max) by 34% (P < .006) and shortened tau by 30% (P < .001). Left ventricular end-systolic elastance increased from 1.2 +/- 0.6 to 2.2 +/- 1 mm Hg/mL (P < .001). Left ventricular energy efficiency increased by 36% (P < .002). Left ventricular mechanical dyssynchrony decreased during systole by 33% (P < .001) and during diastole by 20% (P < .005). CONCLUSIONS: Left ventricular restoration induced acute improvements in contractile state, energy efficiency, and relaxation, together with a decrease in left ventricular mechanical dyssynchrony.

Aged↗
PubMed2005

Surgical ablation of atrial fibrillation with a novel bipolar radiofrequency device.

OBJECTIVE: When used for epicardial ablation, unipolar devices do not predictably yield transmural scars. Bipolar radiofrequency proved highly effective on the animal model, but clinical experience is still initial. We describe acute electrophysiologic findings and follow-up results of epicardial ablation with a novel bipolar radiofrequency device. METHODS: A bipolar ablator was used to perform a simplified left atrial lesion set in 90 consecutive patients with atrial fibrillation undergoing open heart surgery. Pacing thresholds were assessed during surgery to validate 24 pulmonary vein encircling lines (12 patients). Follow-up was 100% complete. RESULTS: In 67 of 90 patients (84%), mitral valve disease was the main indication to surgery. Atrial fibrillation was continuous in 74 patients (82%) and intermittent in 16 patients (18%). Pacing threshold assessment showed a complete conduction block in 22 of 24 pulmonary vein couples (92%) after a single ablation and in all patients after doubling of the encircling lines. No complications related to the ablation procedure were recorded. The sinus rhythm restoration rate was 79% at 3 months, 87% at 6 months, and 89% (17/18 patients) at 1 year. Postablation organized arrhythmias consisted in right atrial flutter in 2 patients (2%) and left atrial flutter in 6 patients (7%). CONCLUSIONS: Epicardial ablation with bipolar radiofrequency grants acute transmurality. A simplified lesion set proved highly effective in eliminating atrial fibrillation at 1-year follow-up. Our data suggest that addition of a lesion to the mitral annulus is advisable to prevent left atrial flutter.

Aged↗
PubMed2005

Off-pump coronary artery bypass grafting reduces postoperative neurologic complications.

OBJECTIVE: Complications occurring after coronary artery bypass graft (CABG) surgery, particularly neurologic damage, have been mainly correlated with the use of cardiopulmonary bypass (CPB). The aim of this work was to compare postoperative outcomes of patients undergoing CABG surgery, with or without the use of CPB, focusing on neurologic events. DESIGN: Observational study. SETTING: University tertiary care hospital. PARTICIPANTS: Two thousand seven hundred and forty consecutive patients who underwent CABG surgery in the period January 1998 to January 2003. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: For 738 patients, the operation was performed off-pump (OP group), and for 2002 patients CPB was used (CPB group). OP and CPB groups were compared with regard to preoperative status, anesthetic management, and postoperative outcomes, by means of univariate and multivariate analyses. Surgeons' propensity to operate off-pump was based on patients' age, renal conditions, and hemodynamics. Univariate and multivariate analyses showed that CPB was associated with a higher incidence of type I neurologic events compared with OP technique (2.1% versus 0.9%, odds ratio [OR]: 2.6, 95% confidence interval [CI], 1.2-5.9). A history of previous stroke (OR: 2.7, 95% CI, 1.2-5.9) and advanced age (OR: 1.06 per year, 95% CI, 1.02-1.09) were additional independent predictors of postoperative type I neurologic events. CONCLUSIONS: In the authors' experience, off-pump CABG surgery offers some benefits compared with CPB in respect to major neurologic complications.

Aged↗
PubMed2005

The effect of concomitant radiofrequency ablation and surgical technique (repair versus replacement) on release of cardiac biomarkers during mitral valve surgery.

All patients undergoing heart surgery experience a certain amount of nonspecific myocardial injury documented by the release of cardiac biomarkers and associated with poor outcome. We investigated the role of unipolar radiofrequency ablation of atrial fibrillation on the release of cardiac biomarkers in 71 patients undergoing mitral valve surgery and concomitant left atrial ablation case-matched with 71 patients undergoing isolated mitral surgery. The study was powered to detect a 3 ng/mL difference. There was no difference between the 2 groups in terms of cardiac troponin I (10 +/- 5.3 versus 12 + 10.4 ng/mL; P = 0.7) or creatine kinase-MB (50 +/- 21.8 versus 57 +/- 62.0 ng/mL; P = 0.5) release. Postoperative peak cardiac troponin I levels had univariate associations with the duration of cardiopulmonary bypass (P = 0.002) and aortic cross-clamping (P = 0.001) and with the surgical technique (15 +/- 12 ng/mL for mitral valve replacement versus 9 +/- 4.8 for mitral valve repair; P = 0.0007) at univariate analysis. Mitral valve replacement was the only independent predictor of postoperative peak release of cardiac troponin I identified with multivariate analysis (P = 0.005). Radiofrequency ablation of atrial fibrillation does not significantly increase cardiac biomarker release compared with isolated mitral surgery; mitral valve repair is associated with less release of cardiac biomarkers compared with mitral valve replacement.

Aged↗
PubMed2005

One-year clinical experience with the Acorn CorCap cardiac support device: results of a limited market release safety study in Italy and Sweden.

BACKGROUND: The Acorn CorCap cardiac support device (CSD) is a mesh-like device intended to provide end-diastolic support and reduce ventricular wall stress. Animal studies with the CorCap CSD have demonstrated beneficial reverse remodeling, and preliminary safety studies in patients with heart failure have shown that the device is safe and associated with improved left ventricular (LV) structure and function. The objective of the current study was to further evaluate the safety and efficacy of the CorCap CSD in patients with advanced heart failure. METHODS: Twenty-four patients with dilated cardiomyopathy, severe LV dysfunction, and advanced heart failure (NYHA class II-IV) were enrolled at four centers in Italy and Sweden. All patients underwent CorCap CSD implantation either alone (n = 3) or in combination with mitral valve repair/replacement (n = 13), coronary artery bypass surgery (n = 6), combined mitral valve repair/coronary artery bypass surgery (n = 1) or aneurysmectomy (n = 1). RESULTS: The LV end-diastolic diameter decreased from 69.3 +/- 7.2 to 60.1 +/- 9.0 mm at 3 months, 60.9 +/- 9.6 mm at 6 months, and 58.9 +/- 8.0 mm at 12 months (all p < 0.05). A trend toward an improved LV ejection fraction (28.8 +/- 10.5% at baseline and 32.4 +/- 12.7, 33.1 +/- 10.8, and 33.8 +/- 13.9% at 3, 6 and 12 months respectively) was also noted. The NYHA functional class, 6-min walking distance, and quality of life as measured using Uniscale were all improved. There were no differences in response among the patients submitted to the different types of concomitant surgery. CONCLUSIONS: In agreement with earlier safety studies, even the present investigation demonstrated improvements in cardiac structure and function as well as in patient functional status after Cor Cap CSD implantation. Randomized controlled trials are in progress.

Adult↗
PubMed2004

Early detection by the Tei index of carvedilol-induced improved left ventricular function in patients with heart failure.

Twenty-two patients (19 men) with heart failure (16 ischemic, 6 dilated cardiomyopathy; mean age of 67 +/- 6 years) in New York Heart Association classes I (2 patients), II (18 patients), and III (2 patients) under optimal therapy were strictly monitored after carvedilol supplementation. The Tei index decreased significantly from 0.87 +/- 0.17 to 0.53 +/- 0.29 (p <0.03). Conversely, the ejection fraction and transmitral Doppler flow analysis did not show significant improvement, despite a trend toward the amelioration of the ejection fraction, the E-/A-wave ratio, and atrial contribution. The Tei index could represent an earlier marker to evaluate drug-induced left ventricular function improvement in patients with heart failure and could represent a more sensitive tool to monitor left ventricular function during drug interventions.

Adrenergic alpha-Antagonists↗
PubMed2004

Prevention of iatrogenic atrial tachycardia after ablation of atrial fibrillation: a prospective randomized study comparing circumferential pulmonary vein ablation with a modified approach.

BACKGROUND: Circumferential pulmonary vein ablation (CPVA) is effective in curing atrial fibrillation (AF), but new-onset left atrial tachycardia (AT) is a potential complication. We evaluated whether a modified CPVA approach including additional ablation lines on posterior wall and the mitral isthmus would reduce the incidence of AT after PV ablation. METHODS AND RESULTS: A total of 560 patients (291 men, 52%; age, 56.5+/-7.3 years) entered the study; 280 were randomized to CPVA alone (group 1) and 280 to modified CPVA (group 2). The primary end point was freedom from AT after the procedure. In group 1, 28 patients (10%) experienced new-onset AT, and 41 (14.3%) experienced recurrent AF. In group 2, 11 patients (3.9%) experienced AT, and 36 (12.9%) had recurrent AF. Group 1 was more likely to experience AT than group 2 (P=0.005). Freedom from AF after ablation was similar in both groups (P=0.57). Among those in group 1, gap-related macroreentrant AT was documented in 23 of the 28 patients (82%), and focal AT was found in 5 (18%). In group 2, gap-related macroreentrant AT was found in 8 of the 11 patients (73%), and focal AT was seen in 3 (27%). Two patients in group 1 and 1 patient in group 2 had both AT and AF. The strongest predictor of AT was the presence of gaps (P<0.001). CONCLUSIONS: Modified CPVA is as effective as CPVA in preventing AF but is associated with a lower risk of developing incessant AT.

Aged↗
PubMed2004

Regional left atrial interstitial remodeling in patients with chronic atrial fibrillation undergoing mitral-valve surgery.

Ablation of the left atrial free wall around the pulmonary vein ostia (LAFW) may be effective in the treatment of chronic atrial fibrillation associated with mitral disease (CAF-MVD). Using light and conventional electron microscopy analyses, we wanted to evaluate, in CAF-MVD, the interstitial remodeling in the LAFW as well as in a more remote region, such as the left atrial appendage (LAA). LAFW and LAA samples were obtained from 33 CAF-MVD patients during combined mitral surgery and radiofrequency ablation and from 16 autoptic controls. Interstitial fibrosis (IF) and perivascular fibrosis (PF), capillary densities and the maximal oxygen diffusion distance were morphometrically determined. In CAF-MVD patients, the LAFW, compared with the LAA, showed a higher percentage of IF (7.16+/-3.23% versus 2.51+/-1.40%, respectively), a lower myocardial capillary density per mm(2) (830+/-106 versus 989+/-173) and an increased oxygen maximal diffusion distance (19.70+/-1.27 microm versus 18.13+/-1.58 microm). All these values were also significantly different than controls. No differences were found in evaluating PF. At variance with the LAA, in CAF-MVD patients, the LAFW around the pulmonary vein ostia is a region characterized by a marked interstitial remodeling such that it may be morphologically indicated as an appropriate target for ablation treatment aimed at sinus rhythm restoration.

Adult↗
PubMed2004

Atrio-esophageal fistula as a complication of percutaneous transcatheter ablation of atrial fibrillation.

BACKGROUND: Radiofrequency ablation for atrial fibrillation is becoming widely practiced. METHODS AND RESULTS: Two patients undergoing circumferential pulmonary vein ablation for atrial fibrillation in different centers developed symptoms compatible with endocarditis 3 to 5 days after the procedure. Their clinical condition deteriorated rapidly, and both suffered multiple gaseous and/or septic embolic events causing cerebral and myocardial damage. One patient survived after emergency cardiac and esophageal surgery; the other died of extensive systemic embolization. An atrio-esophageal fistula was identified in both patients. CONCLUSIONS: Atrio-esophageal fistulas can occur after catheter ablation in the posterior wall of the left atrium. This diagnosis should be excluded in any patient with symptoms or signs of endocarditis after left atrial ablation, and expeditious cardiac surgery is critical if the diagnosis is confirmed. Lower power and temperature settings for applications of radiofrequency energy along the posterior left atrial wall may prevent further cases of fistula formation.

Adult↗
PubMed2004

Pulmonary vein denervation enhances long-term benefit after circumferential ablation for paroxysmal atrial fibrillation.

BACKGROUND: There are no data to evaluate the relationship between autonomic nerve function modification and recurrent atrial fibrillation (AF) after circumferential pulmonary vein ablation (CPVA). This study assesses the incremental benefit of vagal denervation by radiofrequency in preventing recurrent AF in a large series of patients undergoing CPVA for paroxysmal AF. METHODS AND RESULTS: Data were collected on 297 patients undergoing CPVA for paroxysmal AF. Abolition of all evoked vagal reflexes around all pulmonary vein ostia was defined as complete vagal denervation (CVD) and was obtained in 34.3% of patients. Follow-up ended at 12 months. Heart rate variability attenuation, consistent with vagal withdrawal, was detectable for up to 3 months after CPVA, particularly in patients with reflexes and CVD, who were less likely to have recurrent AF than those without reflexes (P=0.0002, log-rank test). Only the percentage area of left atrial isolation and CVD were predictors of AF recurrence after CPVA (P<0.001 and P=0.025, respectively). CONCLUSIONS: This study suggests that adjunctive CVD during CPVA significantly reduces recurrence of AF at 12 months.

Atrial Fibrillation↗