Metformin therapy and risk of cancer in patients after heart transplantation.

BACKGROUND: Diabetes mellitus (DM) and malignancy are recognized among the most common complications increasing mortality in patients after heart transplantation (HTx). Clinical trials have shown a higher risk for different types of tumours in diabetic patients. This risk is potentiated by immunosuppressive therapy in transplant patients. Biguanide metformin has been shown to exhibit anti-tumour activity and we tried to find out whether this effect is valid for heart transplant patients. METHODS: We retrospectively analysed a group of 497 patients, who undergone HTx in our centre between 1998 and 2019. The primary outcome was any malignancy during the 15-year follow-up period and patient's survival. RESULTS: Out of the 497 patients enrolled in the study, 279 (56 %) had diabetes and 52 (19 %) were treated with metformin. Fifteen-year survival in treated patients without malignancy was 93 %, the remainder for the DM patients was 56 %, with survival in non-DM patients being 74 %. Untreated diabetic patients had 4.7 times higher chance of malignancy than those on metformin (p = 0.01). Fifteen-year survival in metformin treated patients was 53 %, in other DM patients 44 %, and in non-DM patients 51 %. CONCLUSION: Our study showed a significantly lower incidence of malignancies in metformin-treated patients and slightly better overall survival (Tab. 2, Fig. 3, Ref. 19) Keywords: biguanide, heart graft, malignancy, diabetes mellitus, survival.

Association between the heart rate early after heart transplantation and the long term clinical outcomes.

BACKGROUND: A strong correlation between a lower heart rate and survival has been demonstrated in various patient populations. The optimal heart rate for heart transplant patients is still unknown. The aim of our study was to evaluate the association between an early heart rate and survival after heart transplantation. MATERIAL AND METHODS: We retrospectively analysed a group of 330 patients, who underwent heart transplantation in our institution from 1994 to 2014 and complete datasets, including 24-hour heart rate monitoring one month after the heart transplantation. Patients were divided in 2 groups: Group A (n = 278) with the average 24-hour heart rate <90 bpm, and Group B (n = 52) with ≥ 90 bpm. RESULTS: The average period of monitoring was 7.5 ± 5.3 years. No differences in baseline characteristics were observed in both groups of recipients and respective donors. One-year survival in groups A and B was 92 % and 81 %, respectively; 5-year survival was 79 % and 60 %, respectively; and 10-year survival was 66 % and 50 %, respectively (p = 0.001). CONCLUSION: Increased heart rate in the early post-transplant period was significantly associated with a poorer survival rate in patients after heart transplantation (Tab. 2, Fig. 1, Ref. 25).

[Heart transplantation]. / Transplantace srdce.

The first heart transplantation (SHT) was performed by Professor Ch. Barnard in 1967 but it was not until 1980s that this method became an established approach to treatment of patients with end-stage heart failure. Considering the limited number of donor organs and the number of potential post-transplantation complications, the decision to perform heart transplantation at the right time in an indicated patient is difficult and complex. Subsequent pharmacological management with immunosuppressive agents and other medication becomes everyday life reality. Knowledge of drug interactions and collaboration with cardiologists are necessary in order to maintain long-term treatment success. Despite the current developments in surgical methods, examination methods and immunosuppressant therapy, a range of complications has to be dealt with. The future of care for patients with transplants will rely on the development of new immunosuppressive drugs with a minimum of adverse effects and discovery of a non-invasive technique for graft rejection diagnosis.

Coronary artery bypass grafting in patients with left ventricular ejection fraction of 30% or less.

BACKGROUND: The results of a merely pharmacological therapy in patients with advanced left ventricular dysfunction are unsatisfactory. Coronary artery bypass grafting is frequently the only therapeutic option, but ventricular dysfunction is generally considered to be a risk factor. AIM: To find out the frequency of coronary artery bypass grafting and its outcome in patients with a ejection fraction of 30% or less who were operated on at a single institution. METHODS: Between January 1st, 1996 and October 30th, 1999, 90 patients (4.6% of all patients operated on due to of coronary artery disease) with EF of 30% or less underwent coronary artery bypass grafting. This group consisted of 12 women and 78 men at an average age of 60.2 +/- 9.4 years (range, 33 to 78 years); 75.6% patients were in functional class III or IV and 80.0% had three-vessel disease. On the average, 2.5 grafts per patient were implanted, the left internal mammary artery was used in 24.4% patients, and 10.0% of patients had cardiac surgery without cardiopulmonary bypass. RESULTS: Hospital mortality was 10%. The main cause of death was cardiac or multiorgan failure. Low cardiac output syndrome and supraventricular dysrrhythmias were the most common postoperative complications. Advanced age and low cardiac output syndrome were found to be risk factors of early mortality. Five other patients died during the follow-up (4 to 48 months). One- and three-year survival rate were 83.1% and 81.9%, respectively. Ejection fraction improved during the follow-up from 27.5% to 33.7%. The improvement was more pronounced in patients in whom preoperative end-diastolic diameter of the left ventricle was below 70 mm, and in patients with two and more hibernating segments on dobutamine stress echo. CONCLUSIONS: Successful results of surgical revascularization in patients with severe impairment of left ventricular function can be achieved by careful selection of patients (the presence of viable myocardium is necessary) and management. Early mortality and morbidity was higher than in patients with normal ventricular function. Age and low cardiac output syndrome were revealed as risk factors of early mortality. Long-term prognosis for hospital survivals was satisfactory. (Tab. 5, Fig. 1, Ref. 13.)