Stenting unprotected left main coronary artery stenosis in heart transplant patients--the good, bad, and the ugly

Treatment of allograft vasculopathy in heart transplantation

Cardiac allograft vasculopathy remains one of the main causes of morbidity and mortality after heart transplantation, although its impact is becoming somewhat smaller as prophylactic measures are implemented. Advances in the understanding of the molecular and cellular mechanisms involved in the genesis and development of cardiac allograft vasculopathy are opening ways for new diagnostic and therapeutic strategies. Successful prophylaxis of the early stages of the disease has been demonstrated with the use of newer immunosuppressive agents, such as sirolimus and everolimus, that will probably be included in future protocols. For most patients with established cardiac allograft vasculopathy, currently available revascularisation methods and retransplantation are not appropriate options. Antiproliferative agents could provide significant improvement in terms of symptom relief and prognosis, but their definite value must be proven in well-designed trials.

Inflammatory Response and Re-stenosis After Percutaneous Coronary Intervention in Heart Transplant Recipients and Patients With Native Atherosclerosis

BACKGROUND

The clinical benefit of percutaneous coronary intervention (PCI) in heart transplant recipients (HTRs) with coronary allograft vasculopathy (CAV) has been questioned. We investigated the degree of inflammatory reaction during PCI in CAV compared to patients with native atherosclerosis, and the possible relationship between PCI-induced inflammation and the degree of re-stenosis in these 2 patient groups.

METHODS

In 11 CAV patients and 10 patients with native atherosclerosis, blood samples were drawn before and 24 hours and 6 months after PCI, and analyzed with regard to hsCRP, MCP-1, components of complement activation, von Willebrand factor (vWf), soluble L-selectin and ICAM-1. Quantitative angiography was performed before and after PCI, and at 6-month follow-up.

RESULTS

Baseline levels of hsCRP, vWf and MCP-1 were significantly elevated and levels of L-selectin and ICAM-1 and activation products of the alternative pathway of the complement system were decreased in CAV patients compared to those with native atherosclerosis. PCI induced significant increases of hsCRP in both groups as well as an increase in vWf in native atherosclerosis, whereas a decrease in L-selectin was observed in native atherosclerosis. Plasma levels of MCP-1 correlated with percent stenosis at follow-up in both groups, whereas a correlation between hsCRP and percent stenosis was evident only in patients with native atherosclerosis. There were no differences in rates of re-stenosis between the 2 groups.

CONCLUSIONS

HTRs with CAV and patients with native atherosclerosis are characterized by different profiles of immune activation and respond differently to PCI. Nevertheless, an inappropriate inflammatory reactivity may predispose to re-stenosis after PCI in both groups of patients, with pre-procedural inflammation being of particular importance in CAV.

Donor-transmitted coronary atherosclerosis

BACKGROUND

Autopsies show that coronary atherosclerosis is present frequently in the young and healthy. However, according to our former guideline, we performed pre-transplant evaluation without coronary angiogram in donors <60 years. The purpose of this study is to evaluate to what extent native coronary atherosclerosis is transmitted through heart transplantation.

METHODS

Between April 1986 and December 2000, a total of 1253 patients underwent heart transplantation at our institution. If coronary evaluation with coronary angiogram or autopsy had been performed within 6 months after transplantation, we regarded focal and non-circumferential atherosclerosis with >or=50% stenosis in proximal segments of at least 1 coronary vessel of the donor heart as transmitted, native coronary atherosclerosis, rather than newly developed transplant vasculopathy.

RESULTS

We excluded 85 of 1253 (6.8%) cases because coronary evaluation was not performed within 6 months (n = 45) or because hearts underwent angiography during pre-transplant evaluation (n = 40). Of these, 2 patients with significant coronary atherosclerosis underwent transplantation and concurrent coronary artery bypass grafting. The prevalence of significant (stenosis >or=50%) and inadvertently transmitted coronary atherosclerosis was 7.0% (82/1168).

CONCLUSION

The prevalence of coronary atherosclerosis in patients who underwent angiography within 6 months after transplantation was 5.2% (49/950). Among subjects who had autopsies within the first 6 months after heart transplantation, we found significant coronary atherosclerosis (stenosis >or=50%) 15.1% (33/218), and among those with early graft failure (<10 days after transplantation), the prevalence was 22.8% (26/114). The prevalence of coronary atherosclerosis in the donor pool is high, and donor screening without coronary angiogram overlooks significant coronary atherosclerotic lesions (stenosis >or=50%) in a considerable number of cases (7.0%). Because donor-transmitted coronary atherosclerosis is a risk factor in short-term (early graft failure) survival after heart transplantation, we have now changed our policy to include coronary angiography as a standard in screening donors >or=40 years. However, to what extent donor coronary atherosclerosis is accepted undoubtedly must be made arbitrarily until an evidence-based algorithm becomes available.