Left ventricular mass regression following aortic valve replacement with mechanical valves

Objective The degree of Left Ventricular Mass Index (LVMI) regression following aortic valve replacement correlates with long-term survival. This study aims to assess the extent of LVMI regression at 3 months following aortic valve replacement (AVR) with different types and sizes of mechanical valves in rheumatic aortic valve disease. Methods The LVMI regression was studied in 34 consecutive patients, undergoing elective AVR for rheumatic aortic stenosis and/or regurgitation. They were grouped in A and B, matched in age, body surface area and pre-operative LVMI, receiving respectively a tilting disc and a bileaflet mechanical valve. The LVMI was calculated by M-mode echocardiography using the Devereux' formula pre-operatively and three months post-operatively. The trend of LVMI reduction was compared between the two groups and amongst the patients with stenotic, regurgitant and mixed aortic valve, pathologies; and receiving different sizes of valves. Results The mean preoperative LVMI was 199g±79.5 g/m². At three months post aortic valve replacement, the mean LVMI was 130g±49.0 g/m². There was a significant reduction of LVMI post-operatively (p=0.001) at three months follow-up. The extent of LVMI regression following surgery amongst the groups A and B did not vary significantly (p=0.92). The extent of LVMI regression did not vary significantly in patients with different aortic valve pathology nor with different sizes of the valves implanted. Conclusions There is a significant early LVMI regression following aortic valve replacement in rheumatic aortic valve disease. The type and the size of the mechanical prosthesis or the rheumatic pathology do not appear to influence this regression.     

Decorin inhibition of PDGF-stimulated vascular smooth muscle cell function: potential mechanism for inhibition of intimal hyperplasia after balloon angioplasty

Decorin is a small proteoglycan that binds to transforming growth factor-beta (TGF-beta) and inhibits its activity. However, its interaction with platelet-derived growth factor (PDGF), involved in arterial repair after injury, is not well characterized. The objectives of this study were to assess decorin-PDGF and decorin-PDGF receptor (PDGFR) interactions, the in vitro effects of decorin on PDGF-stimulated smooth muscle cell (SMC) functions and the in vivo effects of decorin overexpression on arterial repair in a rabbit carotid balloon-injury model. Decorin binding to PDGF was demonstrated by solid-phase binding and affinity cross-linking assays. Decorin potently inhibited PDGF-stimulated PDGFR phosphorylation. Pretreatment of rabbit aortic SMC with decorin significantly inhibited PDGF-stimulated cell migration, proliferation, and collagen synthesis. Decorin overexpression by adenoviral-mediated gene transfection in balloon-injured carotid arteries significantly decreased intimal cross-sectional area and collagen content by approximately 50% at 10 weeks compared to beta-galactosidase-transfected or balloon-injured, non-transfected controls. This study shows that decorin binds to PDGF and inhibits its stimulatory activity on SMCs by preventing PDGFR phosphorylation. Decorin overexpression reduces intimal hyperplasia and collagen content after arterial injury. Decorin may be an effective therapy for the prevention of intimal hyperplasia after balloon angioplasty.     

Mechanical heart valve prostheses:: identification and evaluation (erratum)

Mechanical heart value prostheses have been in use since the 1950s. Many prostheses have been used for a while and then discontinued. Today, there are a large number and variety of prostheses in use and an even larger variety that are in place in patients. These may be explanted at any time for a number of reasons. It is essential for the practicing pathologist to be able to identify the prosthesis and be aware of some of its reported complications and modes of failure. This article, and a second one on bioprosthetic heart valves, is designed as a ready reference guide to heart valve prostheses, their important identifying features, their common complications, and modes of failure. It should help in the accurate identification of explanted prosthetic valves and more definitive reports. This accuracy of identification as well as tracking of abnormalities noted will, we hope, permit the identification of new failure modes and the recording of causes of failure of new (or even modified) prosthetic heart valves.     

Minimally invasive cardiac surgery for removal of the greater saphenous vein

Objective

To determine if saphenous vein required for coronary bypass could be quickly, easily and safely removed with a minimally invasive technique.

Design

A consecutive series.

Setting

A university centre.

Material and Methods

In cadavers, a standard mediastinoscope was used to remove segments of the greater saphenous vein. Thigh segments, superior leg segments and ankle segments were removed. Fifteen minutes were allowed for removal of a segment.

Results

Segments of vein 15 to 17 cm long could be removed. One segment could not be removed within 15 minutes. Thigh segments were easy to remove, calf segments were the most difficult. There were no avulsed side branches. All incisions were less than 5 cm long.

Conclusions

Saphenous vein can be harvested quickly and safely by a minimally invasive method. Lower extremity complications may be reduced and long-term patency improved with this in-situ technique of vein removal.     

Mechanical complications of myocardial infarction

Acute myocardial infarction is responsible for a significant proportion of morbidity and mortality in patients with ischaemic heart disease. Apart from cardiogenic shock, important mechanical complications include myocardial rupture, mitral regurgitation, mural thrombosis, left ventricular true aneurysm and pericarditis. Such patients are likely to be older (more than 60 years of age), especially women with hypertension, single-vessel disease, first episode of transmural infarction, smaller area of infarction, and/or delayed thrombolytic therapy. The incidences of all these complications have significantly reduced due to availability of reperfusion techniques. Myocardial rupture includes rupture of the left ventricular free wall, interventricular septum or papillary muscles, which can occur within few hours or days after infarction and emergency surgery is indicated. Lateral displacement of papillary muscles due to post-infarctional left ventricular remodelling is the main factor for ischaemic mitral regurgitation; some patients would require mitral valve repair or replacement. Mural thrombosis results from an abnormal flow and local hypercoagulable state and requires thrombolytic therapy or even surgical excision. Post-infarctional fibrosis is also responsible for formation of ventricular apical aneurysms and depending on the clinical status, reconstructional surgery may be required. Dressler's syndrome is a rare occurrence of fibrinous pericarditis accompanied by constitutional symptoms, which responds to immunomodulation.     

Cardiac sarcoidosis: Recurrent disease in a heart transplant patient following pulmonary tuberculosis infection

Cardiac transplantation is indicated for patients with end-stage cardiomyopathy secondary to cardiac sarcoidosis. Although rare, recurrent disease has been reported in two cases. The current report presents a case of recurrent cardiac sarcoidosis in a patient 45 months postorthotopic heart transplantation and 40 months following reactivation of latent Mycobacterium tuberculosis infection. The patient was the first to have recurrent disease following an infection that has been proposed to be involved in its pathogenesis. The patient’s interval between transplant and recurrence is the longest reported to date.