Hypertrophic obstructive cardiomyopathy caused by Fabry disease: implications for surgical myectomy.

Hypertrophic obstructive cardiomyopathy can be the phenotype of storage disorders as Fabry disease cardiomyopathy. In this instance, its recognition through GLA gene analysis and preventive administration of enzyme replacement therapy may reduce heart failure risk of surgical septal myectomy (SSM). A 59-year-old man was referred for SSM as dyspnoea and low threshold muscle fatigue associated to severe left ventricular outflow obstruction (gradient of 100 mmHg) due to both interventricular septal hypertrophy and mitral leaflet systolic anterior motion were not controlled by metoprolol 100 mg bid. Electrocardiogram showed sinus rhythm and a complete left bundle branch block. Cardiac magnetic resonance imaging showed a preserved left ventricular (LV) contractility (ejection fraction 70%) but failed to reveal reduced T1 mapping and fibrosis of postero-lateral LV wall suggesting Fabry disease cardiomyopathy. Cardiac catheterization and coronary angiography documented increased LV end-diastolic pressure but normal coronary arteries. SSM was followed by acute renal and heart failure with left ventricular ejection fraction declining to 35%. Histology of SSM showed regularly arranged severely enlarged cardiomyocytes containing extensive vacuoles that were intensely positive to immunofluorescence with anti-Gb3 antibodies and appeared at electron microscopy to consist of myelin bodies suggesting the diagnosis of FD. This entity was confirmed by low blood levels of alpha-galactosidase A (0.8 nmol/mL/h; NV > 1), high values of Lyso-Gb3 (5.85 nmol/L; NV < 2.3), and the presence of the pathogenic mutation c.644A>G in the exon 5 of GLA gene. This study emphasizes the importance of a genetic screening for FD before SSM be considered for hypertrophic obstructive cardiomyopathy.

Giant Right Coronary Artery Aneurysm Detected by Transthoracic Echocardiography.

Coronary artery aneurysms (CAAs) are rare findings caused by atherosclerosis in about 50% of cases. They are usually diagnosed using coronary angiography, cardiac computed tomography, or magnetic resonance imaging. In this report, we present a rare case of giant, isolated right CAA, detected by transthoracic echocardiography in an adult patient with unstable angina. Diameters of the aneurysm were 3.6 cm × 2.7 cm. Anterior-septal hypokinesia of the left ventricle was also noted. A comprehensive echocardiographic examination, including contrast study, excluded alternative diagnoses and supported the hypothesis of a coronary ectasia. The coronary angiography confirmed the diagnosis of giant coronary aneurysm and revealed a severe three-vessel disease. The patient was treated with cardiac surgery a few days later: two coronary artery bypass grafts and exclusion of the aneurysm by surgical legation were successfully performed.

Transaortic Chordal Cutting: Mitral Valve Repair for Obstructive Hypertrophic Cardiomyopathy With Mild Septal Hypertrophy.

BACKGROUND: In severely symptomatic patients with obstructive hypertrophic cardiomyopathy (HCM) and mild septal hypertrophy, mitral valve (MV) abnormalities may play an important role in MV displacement into the left ventricular (LV) outflow tract. Therefore, isolated myectomy may not relieve outflow obstruction and symptoms, and MV replacement is often the surgical alternative. OBJECTIVES: This study sought to assess the clinical and hemodynamic results of cutting thickened secondary MV chordae combined with a shallow septal muscular resection in severely symptomatic patients with obstructive HCM and mild septal hypertrophy. METHODS: Clinical features were compared before surgery and at most recent clinical evaluation in 39 consecutive patients with obstructive HCM. RESULTS: Over a 23 ± 2 months follow-up, New York Heart Association functional class decreased from 2.9 ± 0.5 pre-operatively to 1.1 ± 1.1 post-operatively (p < 0.001), with no patient in class III at most recent evaluation. The resting outflow gradient decreased from 82 ± 43 mm Hg to 9 ± 5 mm Hg (p < 0.001) and septal thickness decreased from 17 ± 1 mm to 14 ± 2 mm (p < 0.001). No patient had MV prolapse or flail and 1 had residual moderate-to-severe MV regurgitation at most recent evaluation. MV geometry before and after surgery was compared with that of 25 consecutive patients with similar clinical profile and septal thickness that underwent isolated myectomy. After adjustment for differences in pre-operative values between the groups, the post-operative anterior MV leaflet-annulus ratio was 17% greater and tenting area 24% smaller in patients with chordal cutting, indicating that MV apparatus had moved to a more normal posterior position within the LV cavity, preventing MV systolic displacement into the outflow tract and outflow obstruction. CONCLUSIONS: This procedure relieves heart failure symptoms, abolishes LV outflow gradient, and avoids MV replacement in patients with obstructive HCM and mild septal thickness.

A contemporary European experience with surgical septal myectomy in hypertrophic cardiomyopathy.

AIMS: The recent American College of Cardiology and American Heart Association Guidelines on hypertrophic cardiomyopathy (HCM) have confirmed surgical myectomy as the gold standard for non-pharmacological treatment of obstructive HCM. However, during the last 15 years, an extensive use of alcohol septal ablation has led to the virtual extinction of myectomy programmes in several European countries. Therefore, many HCM candidates for myectomy in Europe cannot be offered the option of this procedure. The purpose of our study is to report the difficulties and results in developing a myectomy programme for HCM in a centre without previous experience with this procedure. METHODS AND RESULTS: The clinical course is reported of 124 consecutive patients with obstructive HCM and heart failure symptoms who underwent myectomy at a single European centre between 1996 and 2010. The median follow-up was 20.3 months (inter-quartile range: 3.9-40.6 months). No patients were lost to follow-up. A cumulative incidence of HCM-related death after myectomy was 0.8, 3.3, and 11.2% at 1, 5, and 10 years, respectively, including one operative death (procedural mortality 0.8%). The left ventricular (LV) outflow gradient decreased from 95 ± 36 mmHg before surgery to 12 ± 6 mmHg at most recent evaluation (P < 0.001), with none of the patients having a significant residual LV outflow gradient. Of the 97 patients in New York Heart Association functional class III-IV before surgery, 93 (96%) were in class I-II at most recent evaluation (P < 0.001). CONCLUSION: Our results show that the development of a myectomy programme at a centre without previous experience with this procedure is feasible and can lead to highly favourable clinical results.

[Present and future options for the surgical treatment of patients with advanced heart failure]. / Che novità possiamo attenderci dalla terapia chirurgica dello scompenso cardiaco avanzato.

Despite considerable improvement in the medical treatment of heart failure, cardiac transplantation remains the gold standard for the treatment of end-stage patients. However, organ shortage forces to look for alternative therapies. A number of innovative approaches are being investigated in terms of improved survival and quality of life in patients refractory to medical therapy. The main cause of heart failure is represented by ischemic cardiomyopathy, responsible for up to 65% of its prevalence in the population. Long-term survival of patients affected by advanced heart failure due to ischemic cardiomyopathy is still unsatisfactory, in spite of improved medical therapy. Besides heart transplantation and the implantation of ventricular assist devices, a surgical option is represented by conventional heart surgery, consisting of myocardial revascularization associated with surgical ventricular restoration, correction of mitral valve regurgitation, and cardiac resynchronization therapy. The STICH trial (Surgical Treatment for Ischemic Heart Failure), an international multicenter trial sponsored by the US National Heart Lung and Blood Institute, will provide important information regarding the effectiveness of such surgical treatment. A new therapeutic option could be represented in the next future by the clinical use of intracardiac elastic devices, currently under investigation, which can be implanted at the mitral annulus and at the level of the left ventricular equator.

Toward the development of a fully elastic mitral ring: preliminary, acute, in vivo evaluation of physiomechanical behavior.

OBJECTIVES: The optimal repair of functional mitral regurgitation is still debated. No device is able to simultaneously abolish mitral regurgitation and replicate natural mitral annular dynamics. We have tested a fully elastic mitral ring in an acute animal study with the purpose of evaluating (1) ring design and implantation technique, (2) elastic performance, and (3) acute effects on the native mitral annulus. METHODS: Ten healthy sheep underwent surgical implantation of mitral devices, the elastic component of which is represented by a helicoid metallic spring. Preimplantation and postimplantation echocardiographic parameter measurements to evaluate annular dynamics and ventricular function comprise mitral annular motion, systolic tissue Doppler imaging peak wave, transmitral pressure gradient, peak transmitral flow velocity, and ejection fraction. Postimplantation angiographic analysis allowed measurement of the mitral annular area and perimeter variations by means of segmentation of the radiopaque mitral device contour. RESULTS: No significant difference in terms of ejection fraction (P = .13) and systolic tissue Doppler imaging peak wave (P = .87) was found before and after implantation. Mitral annular motion (1.16 cm) was preserved. The percentage of systolic annular reduction derived from angiographic analysis was 14.1% (range, 7.7%-19.7%) in terms of area and 7.2% (range, 4.9%-10.0%) in terms of perimeter. CONCLUSIONS: A mitral elastic ring, implantable by using a standard technique, acutely preserves mitral annular dynamics, allowing area and perimeter changes. Further chronic study is needed to verify the biocompatibility and durability of the device.

Coronary ostial enlargement to prevent stenosis after prosthetic aortic valve replacement.

Iatrogenic left and/or right coronary artery ostial stenosis after aortic valve replacement is a rare but life-threatening complication. Although usually related to trauma to the ostium/a during cannulation for administration of cardioplegia, it may be rarely due to direct obstruction by the prosthetic annular ring or stent. We report herein an alternative technique to manage this complication when due to the latter event, successfully utilized at our institution over the last eleven years.

Influence of type 2 diabetes on functional and structural properties of coronary artery bypass conduits.

Recent studies have reported a high incidence of postoperative unfavorable cardiac-related events in patients with diabetes who underwent coronary artery bypass grafting (CABG). Structural and functional characteristics of CABG conduits, which have been shown to play an important role in patient outcome after myocardial revascularization, have not been fully investigated in diabetic subjects. Therefore, we sought to determine the influence of adult-onset diabetes on vasoreactivity and morphological profile of venous and arterial grafts. Of the 160 consecutive patients enrolled in the study, 90 were diagnosed with type 2 diabetes and 70 did not have diabetes (control group). All patients underwent evaluation of glucose control before surgery. Tissue specimens were collected from left internal thoracic artery (LITA) and saphenous vein (SV) grafts harvested during elective CABG. Functional tests were performed to assess contractile and vasodilative responses of bypass conduits. Histological evaluation was carried out to examine vessel wall structure. Univariate and multivariate analyses were performed to correlate the preoperative factors related to the control of the endocrine disorder with histological findings. Patient medical history and demographics did not differ between the groups. Diabetic patients showed significant microalbuminuria and higher plasma levels of C-peptide and GHb as compared with nondiabetic subjects. Functional tests of the LITA segments revealed no difference between groups with regard to contractile and vasodilative responses. In contrast, significant impairment in the endothelium-related vasodilation of the SV grafts was observed in diabetic subjects. Histological studies showed structural preservation of the arterial conduits in both groups. However, marked intimal abnormalities (also atherosclerotic calcified plaques) were detected in SV grafts harvested from diabetic patients. Logistic regression analysis showed that high levels of proteinuria and GHb were independent predictors of advanced structural degeneration of SV conduits. Treatment modality, duration of diabetes, and other demographic or metabolic factors were found to have no influence on the morphological characteristics of SV conduits. In conclusion, biological properties of LITA conduits for CABG were preserved in diabetic patients. However, these patients frequently showed impairment of the endothelium-dependent vasorelaxation and intimal degeneration of SV grafts. The extent of structural abnormalities of SV grafts was inversely correlated with the efficacy of the metabolic control of the endocrine disorder. Further studies are required to conclusively correlate preoperative SV graft abnormalities with postoperative conduit patency rate and the occurrence of adverse cardiac-related events in diabetic subjects.

The CarboMedics prosthetic heart valve: experience with 1,084 implants.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate our clinical experience with the CarboMedics heart valve prosthesis. METHODS: Between October 1991 and December 2000, 942 consecutive patients (514 males, 428 females; mean age 58+/-11 years; range: 6-78 years) underwent mechanical valve implantation with the CarboMedics prosthesis. Preoperatively, 47% of patients were in NYHA class III and 22% in class IV; in addition, 134 patients (14.2%) had undergone a previous cardiac operation. Aortic valve replacement (AVR) was performed in 469 patients (49.8%), mitral valve replacement (MVR) in 330 (35.0%), double valve replacement (DVR) in 142 (15.1%), and isolated tricuspid valve replacement (TVR) in one patient. Eighty-eight patients (9.3%) underwent associated myocardial revascularization. Mean cardiopulmonary bypass and aortic cross-clamp times for the entire group were 107+/-39 min and 74+/-24 min, respectively. RESULTS: Overall early mortality was 2.3% (6/469 AVR, 1.2%; 12/330 MVR, 3.6%; 4/142 DVR, 2.8%). Late mortality was 3.1% (n = 29; including 17 cardiac deaths (10 were valve-related). Mean follow up was 66+/-31 months (range: 1-109 months), and was 98% complete yielding a total follow up of 4959 years. Actuarial survival at five years for the entire group was 89.3+/-1.6% (AVR 91.1%, MVR 86.4%, DVR 90.5%). Thromboembolism occurred in 26 patients (2.8%, 0.52%/pt-year) and major hemorrhagic events in 20 (2.1%, 0.4%/pt-year). Nine patients (0.9%) required a reoperation, in three cases (0.3%) after Staphylococcus epidermidis-mediated endocarditis. No structural deterioration occurred. Among 891 survivors, 94% of the patients are currently in NYHA classes I or II (p <0.05). CONCLUSION: This study confirmed the safety and reliability of the CarboMedics mechanical valve prosthesis, even in old age groups. This bileaflet prosthesis showed no structural deterioration, and a low incidence of overall complications.