Inferior ST-elevation myocardial infarction secondary to coronary artery spasm in a patient on maintenance sirolimus postrenal transplantation

Renal transplantation is the treatment of choice for patients with end-stage renal disease. While transplantation improves the quality of life and reduces the mortality risk for most patients when compared with maintenance dialysis, it introduces significant morbidity associated with induction and maintenance immune suppression. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, is frequently used as a second-line maintenance immunosuppressive agent in solid organ transplant recipients. Sirolimus may, however, have adverse vascular effects and has previously been shown to induce endothelial cell dysfunction and impaired nitric oxide production in vitro. Sirolimus-eluting coronary artery stents have been associated with rare reports of severe coronary artery vasospasm; however, systemic sirolimus therapy has not previously been associated with vasospastic complications.

Cardiac resynchronisation therapy for reversal of new-onset left bundle branch block and heart failure after surgical aortic valve replacement

Left bundle branch block (LBBB) is not an uncommon complication following both surgical aortic valve replacement and transcatheter aortic valve implantation. LBBB can cause interventricular and intraventricular dyssynchrony that can lead to development of heart failure as demonstrated by a decline in left ventricular ejection fraction (LVEF). It is known that change in QRS duration has significant correlation with change in LVEF. In a study involving 202 consecutive patients with no baseline ventricular conduction disturbances or previous permanent pacemaker implantation who underwent transcatheter aortic valve replacement (TAVR) with a balloon-expandable valve, it was found that around 30% of patients develop new LBBB.