Review article: the new concept of interventional heart failure therapy--part 1: electrical therapy, treatment of CAD, fluid removal, and ventricular support

The diagnostic value of three-dimensional CT angiography for patients with acute coronary artery disease

Computed tomography angiography (CTA) is an efficient method for the diagnosis of heart disease. However, few contemporary studies have evaluated the prognostic value of three-dimensional (3D)-CTA for patients with acute coronary artery disease. The aim of the present study was to investigate the diagnostic value of 3D-CTA for patients with acute coronary artery disease. A total of 136 patients with suspected acute coronary artery disease were recruited and received conventional coronary angiography (CCA) and 3D-CTA. 3D-CTA was used to assess calcified plaques in the coronary arteries (CCTA), the ratio of calcified plaque volume to vessel circumference (RVTC) and diagnostic accuracy. The results revealed that 3D-CTA was a more effective diagnostic method for identifying calcified plaques in patients with acute coronary artery disease compared with CCA. 3D-CTA demonstrated a significantly better area under curve, sensitivity, specificity, positive predictive value and negative predictive value compared with CCA (P<0.01). In the present study, 3D-CTA was used to successfully diagnose 86 patients with acute coronary artery disease, 34 with myocardial infarction and 16 with stable angina. 3D-CTA images clearly showed global noise levels and target-to-background ratios determined by manually delineated coronary plaque lesions compared with CCA. Furthermore, 3D-CTA was significantly better for discriminating ischemia compared with CCA (P<0.01). In conclusion, the results of the present study suggest that 3D-CTA provides superior diagnostic performance compared with CCA alone in patients with acute coronary artery disease.

[The chronic critically ill patient from the cardiologist's perspective]

In recent years the prognosis and survival of chronic and acute heart failure (HF) patients has been steadily improving; however, many patients develop advanced chronic HF which is characterized by worsening of symptoms, unplanned hospital admission due to acute decompensation, development of complications, such as life-threatening arrhythmia and shorter life span. Optimal medical therapy is supplemented by interventional cardiology, cardiovascular implantable electronic devices (CIEDs), minimally invasive valve replacement or repair, circulatory mechanical support and heart transplantation. Medical indications and informed consent are essential prerequisites for successfully implementing treatment goals. For patients who are incapable of decisions a legally defined surrogate decision-maker has the same right to refuse or request the withdrawal of treatment as the patient would have if the patient had decision-making capability. As the use of circulatory mechanical support becomes increasingly more prevalent, ethical issues are likely to arise at an increasing rate, as will social and legal ramifications. The concept of turning off an implanted device as death nears is challenging because of ethical and technical concerns. The same holds true for CIEDs. A palliative care approach is applicable to heart failure patients and is particularly relevant to those with advanced disease. Palliative care should be integrated as part of a team approach to comprehensive HF care and should not be reserved for those who are expected to die within days or weeks.

A coupled biventricular finite element and lumped-parameter circulatory system model of heart failure

Numerical modelling of the cardiovascular system is becoming an important tool for assessing the influence of heart disease and treatment therapies. In the current study, we present an approach for modelling the interaction between the heart and the circulatory system. This was accomplished by creating animal-specific biventricular finite element (FE) models, which characterise the mechanical response of the heart, and by coupling them to a lumped-parameter model that represents the systemic and pulmonic circulatory system. In order to minimise computation time, the coupling was enforced in a weak (one-way) manner, where the ventricular pressure-volume relationships were generated by the FE models and then passed into the circulatory system model to ensure volume conservation and physiological pressure changes. The models were first validated by tuning the parameters, such that the output of the models matched experimentally measured pressures and volumes. Then the models were used to examine cardiac function and the myofibre stress in a healthy canine heart and a canine heart with dilated cardiomyopathy. The results showed good agreement with experimental measurements. The stress in the case of cardiomyopathy was found to increase significantly, while the pump function was decreased, compared to the healthy case. The total runtime of the simulations is lesser than that of many fully coupled models presented in the literature. This will allow for a much quicker evaluation of possible treatment strategies for combating the effects of heart failure, especially in optimisation schemes that require numerous FE simulations.