Association between circulating 25-hydroxyvitamin D levels and medication use in patients scheduled for cardiac surgery

BACKGROUND AND AIM

Low vitamin D status, i.e. circulating 25-hydroxyvitamin D (25OHD) levels <50 nmol/l, is independently associated with increased CVD risk. Medication use may influence 25OHD levels. We therefore investigated the association of circulating 25OHD with medication use in patients scheduled for cardiac surgery.

METHODS AND RESULTS

A total of 11,256 patients were included in this cross-sectional study. We compared 25OHD levels of medication users (18 groups of continuously used and 5 groups of intermittently used medications) with levels of non-users. Moreover, we assessed variables (medications, demographic and clinical parameters) that were independently associated with 25OHD levels <50 nmol/l. The prevalence of 25OHD levels <50 nmol/l was 65.7%. The use of statins and immunosuppressive agents was significantly associated with higher 25OHD levels and lower odds ratios of 25OHD levels <50 nmol/l. The use of ACE-inhibitors, catecholamines and antibiotics was associated with lower 25OHD levels and higher odds ratios of 25OHD levels <50 nmol/l. However, only use of antibiotics, immunosuppressive agents and catecholamines showed clinically relevant differences in 25OHD levels, i.e. differences of more than +4 nmol/l or -4 nmol/l, compared with respective non-users. These medications were prescribed either intermittently (antibiotics, catecholamines) and/or infrequently (<2%; immunosuppressive agents, catecholamines) and/or its causal relationship with circulating 25OHD is questionable (antibiotics). Female sex and blood drawing during wintertime were associated with the highest odds ratios of 25OHD levels <50 nmol/l.

CONCLUSION

Data indicate that in patients with high cardiovascular risk profile medication use does not substantially contribute to 25OHD levels <50 nmol/l.

Body mass index, cardiac surgery and clinical outcome. A single-center experience with 9125 patients

BACKGROUND AND AIM

There is evidence for a J-shaped association between Body Mass Index (BMI) and all-cause mortality in general populations. In cardiac surgical patients, the effect of BMI on mortality and major adverse cardiac and cerebrovascular events (MACCE) is not completely clear.

METHODS AND RESULTS

We investigated the effect of BMI on MACCE (primary endpoint), as well as intensive care unit (ICU)-related outcomes and mid-term mortality in 9125 consecutive patients who were operated on at our institution between July 2009 and July 2012. Of the study cohort, 3.0% were underweight (BMI < 20 kg/m(2)), 28.0% had a normal BMI (20-24.99 kg/m(2)), 43.1% were overweight (BMI 25-29.99 kg/m(2)), 19.3% were obese (BMI 30-34.99 kg/m(2)), and 6.6% were severely obese (BMI ≥ 35 kg/m(2)). Compared with overweight patients (lowest incidence of MACCE), the multivariable-adjusted odds ratio of MACCE in severely obese patients was 1.39 (95% CI: 1.03-1.87). Underweight and severely obese patients had the longest risk-adjusted duration of mechanical ventilator support and ICU stay (P-values 0.004-0.001). The red blood cell concentrates requirement was highest in underweight patients (P < 0.001). Compared with normal and overweight patients, the multivariable-adjusted hazard ratio of 2-year mortality was higher in underweight patients (1.72 [95% CI: 1.26-2.36] and =2.07 [95% CI: 1.51-2.83], respectively), but did not differ significantly in severely obese patients.

CONCLUSION

Data demonstrate that both severe obesity and underweight are independent risk factors for operative complications in cardiac surgical patients. With respect to mid-term survival, special attention should be paid to underweight patients scheduled for cardiac surgery.

[Heart and combined heart-lung transplantation. Indications, chances and risks]

Orthotopic heart transplantation (HTX) is nowadays the worldwide accepted gold standard for the treatment of terminal heart failure. The main indications for HTX are non-ischemic dilatative (54%) and ischemic (37%) heart failure. In the acute phase after HTX the survival rate is approximately 90%. Good short and long-term results with survival rates ranging from 81% after 1 year to more than 50% after 11 years demonstrate that there is currently no real treatment alternative to HTX for treatment of end-stage heart failure. In the case of irreversible pulmonary hypertension in combination with end-stage heart failure or complex congenital heart syndromes, a combined heart and lung transplantation (HLTX) is necessary. Compared with HTX the short-term survival of HLTX is reduced, mostly for technical reasons. Improved long-term results after HTX and HLTX are a result of highly specialized transplantation units and effective immunosuppression. However, a major problem is the shortage of organ donors in Germany and the resulting long waiting times for patients with frequently occurring blood groups of up to 10 months for transplantation. The consequence of the latter is the ever increasing number of implanted cardiac assist devices in patients not only as a bridge to transplant but also as destination therapy.

[Hybrid operation theatre from the point of view of cardiac surgery. The future for the heart team]

Nowadays, increasing numbers of procedures jointly conducted by cardiac surgeons and cardiologists are performed as minimally invasive surgical procedures or interventions. Transcatheter aortic valve implantation, endovascular aortic aneurysm repair and a large variety of hybrid procedures for congenital heart disease have become current standards. Some of these hybrid procedures were shown to improve the therapeutic safety and efficacy, effects particularly true for high-risk patients and complex interventions. Hybrid procedures require indirect imaging, commonly provided by an angiography system in the hybrid operation theatre. This article describes the technical prerequisites required for a hybrid operation theatre as well as indications and rationales for hybrid procedures conducted in this environment. It is likely that the indications for cardiovascular hybrid procedures will continue to be expanded and that the hybrid operation theatre may become a laboratory for developing innovative approaches in the cardiovascular field. Therefore, the hybrid operation theatre will not only be the working environment for hybrid surgeons and interventionalists but also help to evolve their future.

Moderate dosage of tranexamic acid during cardiac surgery with cardiopulmonary bypass and convulsive seizures: incidence and clinical outcome

BACKGROUND

Convulsive seizures (CS) occur in ∼1% of the patients after cardiac surgery with cardiopulmonary bypass. Recent investigations indicate an up to seven-fold increase in CS in cardiac surgical patients receiving high doses (≥60 mg kg(-1) body weight) of tranexamic acid (TA).

METHODS

In a retrospective data analysis of 4883 cardiac surgical patients, we investigated the incidence of CS in patients receiving a moderate dose of TA (24 mg kg(-1) body weight) compared with a reference group not receiving TA as a primary endpoint. Secondary endpoints were intensive care unit stay and in-hospital mortality. We performed propensity score (PS)-adjusted logistic regression analysis to test the association between TA use/non-use and clinical outcomes.

RESULTS

Compared with the reference group, the PS-adjusted odds ratio (OR) for CS in the TA group was 1.703 [95% confidence interval (CI): 1.01-2.87; P=0.045; incidence 2.5% vs 1.2%]. Log-ICU-stay was significantly longer (P=0.004) and PS-adjusted relative in-hospital mortality risk was significantly higher for the TA group compared with the reference group (OR=1.89; 95% CI: 1.21-2.96; P=0.005). Both the TA-associated CS incidence and the in-hospital mortality risk were only significant in patients undergoing open-heart surgery (OR=2.034, 95% CI: 1.07-3.87; P=0.034 and OR=2.20, 95% CI: 1.32-3.69; P=0.003, respectively) but not in patients undergoing coronary artery bypass grafting (OR=1.21, 95% CI: 0.49-3.03; P=0.678 and OR=1.13, 95% CI: 0.42-3.02; P=0.809, respectively).

CONCLUSIONS

In open-heart surgery, even moderate TA doses are associated with a doubled rate of CS and in-hospital mortality. Prospective trials are needed to further evaluate the safety profile of TA in cardiac surgery.

Future directions in vitamin D and cardiovascular research

AIMS

Evidence is accumulating that vitamin D status may influence the risk of cardiovascular disease (CVD). Final confirmation for a causal relationship between vitamin D and CVD is however still lacking. The present viewpoint article outlines several future research directions to close this gap.

DATA SYNTHESIS

Future directions include the need of performing large randomised controlled supplementation trials with vitamin D in specific risk groups. In addition, large register sets of data on vitamin D supplementation can be used, provided that adequate statistical methods such as propensity score modelled analysis are applied. To better understand vitamin D-mediated effects on CVD risk, the routine measurement of circulating levels of the hormonal vitamin D form, 1,25-dihydroxyvitamin D, is also necessary, in addition to the determination of its precursor 25-hydroxyvitamin D. Further, genetic association studies may help in clarifying the contribution of vitamin D to the development of CVD. Finally, the interrelationship of vitamin D with physical activity should be considered when studying CVD risk.

CONCLUSIONS

Overall, it can be expected that the next 10-15 years will provide an increased clarity concerning the role of vitamin D in CVD.