Natural history of left-sided valves after heart transplantation

Transcatheter aortic valve implantation for degenerative aortic valve regurgitation long after heart transplantation

Transcatheter aortic valve implantation (TAVI) has become a feasible therapeutic option for the management of high-risk patients with severe degenerative aortic stenosis. Recently it has been extended to high-risk patients with severe aortic regurgitation. Degenerative aortic valve disease is generally uncommon in heart transplant recipients. We report the case of a 75-year-old man in whom severe degenerative aortic regurgitation developed 14 years after heart transplantation (HTx). Because of multiple comorbidities and high surgical risk, TAVI was preferred. A 29-mm CoreValve prosthesis (Medtronic Inc, Minneapolis, MN) was successfully implanted using a transfemoral approach.

Surgical Repair of Mitral and Tricuspid Valves after Cardiac Transplantation

A 43-year-old man underwent mitral valve repair for mitral valve insufficiency due to infective endocarditis, and tricuspid valve repair for iatrogenic chordal rupture due to multiple endomyocardial biopsies after orthotopic cardiac transplantation. Valve repair using no artificial material is feasible, instead of valve replacement, to decrease the risk of recurrent infective endocarditis and enable further biopsies.

Clinical implications of late mitral valve regurgitation appearance in the follow-up of heart transplantation

BACKGROUND

Tricuspid regurgitation is frequently observed after orthotopic heart transplantation (OHT), in association with severe pulmonary hypertension. However, the incidence of left-sided valvular disease has not been addressed.

AIM

We analyzed the incidence and prognostic implications of left-sided valve disease in 141 patients after OHT.

METHODS

Echocardiography was performed with every endomyocardial biopsy during the first year after OHT and every 6 months thereafter. Mitral regurgitation (MR) grade II or III was considered significant. Graft vasculopathy was assessed using coronary angiography.

RESULTS

Eight patients (6%) developed significant left-sided valvular disease, namely, MR in 6 (4%) and aortic regurgitation (AR) in 2 (1.4%). The 2 cases with AR were diagnosed the first week after OHT, whereas significant MR was diagnosed at mean follow- up of 34 +/- 6 months. Mean regurgitant orifice and volume were 34 +/- 14 mm2 and 41 +/- 15 mL/beat, respectively. Patients with significant MR had experienced a greater number of acute rejection episodes >or=3A, (1.8 +/- 1.7 vs 0.8 +/- 1.05; P = .02) and were associated with allograft vasculopathy in 83% vs 6% among unaffected patients (P = .0001). Four of 6 patients with significant MR died during follow-up (67%) and 1 of the living patients underwent reparative mitral valve surgery. The probability of survival using Kaplan-Meier curves was significantly lower when patients developed late significant MR (54% vs 76%; P = .0001).

CONCLUSIONS

The incidence of significant left-sided valvular disease after OHT was low. MR was associated with a higher degree of previous acute rejection, of graft vasculopathy, and mortality. The presence of moderate or severe MR of late appearance identified a group of OHT patients with poor outcomes.

Biological mechanisms influencing the function of the aortic root

Optimal function of the aortic root relies upon the ability of its component structures to move in a coordinated fashion. Some of the cells that make up the structures of the aortic root have been shown to contain nerves, receptors, and contractile elements. The ability to contract or relax may contribute to the successful function of the valve by allowing it to move in a coordinated manner in response to biological stimuli. It is known that cusp tissue receives primary, sensory, and autonomic nerves, suggesting a role for neuronal regulation of cusp function. In addition, cusp tissue has been shown to express a wide variety of receptors and to contract to a range of common vasoactive agents. The cells that constitute the valve have also shown secretory and proliferative responses. The biological signals that mediate the cross-talk between the different parts of the root have not been established. This review will examine the mechanisms that have been documented to be present and to assess their potential contribution in affecting aortic valve function.