Periprocedural prognostic factors in coronary interventions – retrospective studies

Background: Approximately 11,000 revascularization procedures, either percutaneous coronary interventions (PCI) or coronary artery bypass grafting surgery (CABG), are performed yearly in Finland for coronary artery disease. Periprocedural risk factors for mortality and morbidity as well as long-term outcome have been extensively studied in general populations undergoing revascularization. Treatment choice between PCI and CABG in many high risk groups and risk-stratification, however, needs clarification and there is still room for improvement in periprocedural outcomes. Materials and methods: Cohorts of patients from Finnish hospitals revascularized between 2001 and 2011 were retrospectively analyzed. Patient records were reviewed for baseline variables and postprocedural outcomes (stroke, myocardial infarction, quality of life measured by the EQ-5D –questionnaire, repeat revascularization, bleeding episodes). Data on date and mode of death was acquired from Statistics Finland. Statistical analysis was performed to identify predictors of adverse events and compare procedures. Results: Postoperative administration of blood products (red blood cells, fresh frozen plasma, platelets) after isolated CABG independently and dose-dependently increases the risk of stroke. Patients 80 years or older who underwent CABG had better survival at 5 years compared to those who underwent PCI. After adjusting for baseline differences survival was similar. Patients on oral anticoagulation (OAC) for atrial fibrillation (AF) treated with CABG had better survival and overall outcome at 3 years compared to PCI patients. There was no difference in incidence of stroke or bleeding episodes. Differences in outcome remained significant after adjusting for propensity score. Lower health-related quality of life (HRQOL) scores as measured by the visual analogue scale (VAS) of the EQ-5D questionnaire at 6 months after CABG predicted later major adverse cardiac and cerebrovascular events (MACCE). Deteriorating function and VAS scores between 0 and 6 months on the EQ-5D also independently predicted later MACCE. Conclusions: Administration of blood products can increase the risk of stroke after CABG and liberal use of transfusions should be avoided. In the frail subpopulations of patients on OAC and octogenarians CABG appears to offer superior long-term outcome as compared to PCI. Deteriorating HRQOL scores predict later adverse events after CABG. Keywords: percutaneous coronary intervention, coronary artery bypass grafting, age over 80, transfusion, anticoagulants, coronary artery disease, health-related quality of life, outcome.

Nurse-led interpersonal counselling for depressive symptoms in patients with myocardial infarction

The broad interest of this intervention study is in two worldwide remarkable diseases, myocardial infarction and depression. The purpose of the 18-month follow-up study was to evaluate the outcomes of interpersonal counselling implemented by a psychiatric nurse, and to examine the recovery experienced by the patients after myocardial infarction. The interpersonal counseling consisted of a short-term (max 6 sessions) depression-focused intervention modified for myocardial infarction patients. The main principle of interpersonal counselling is that depressive symptoms relate to interpersonal relations. The measured outcomes of the intervention consisted of changes in depressive symptoms and distress, health-related quality of life and the use of health care services. The data consisted of 103 patients with acute myocardial infarction and with sufficient knowledge of Finnish language, and they were randomized into intervention group (n=51) and control group (n=52) with standard care. Depressive symptoms were measured using Beck Depression Inventory, and distress using Symptom Checklist-25. The instrument to measure health-related quality of life was EuroQol-5 Dimensions. All instruments were used at three measurements: in hospital, at 6 months and at 18 months after hospital discharge. The Use of Health Care Services questionnaire was used during the 6- and 18-month period after hospital discharge. In addition, satisfaction with the intervention and with information received from the health-care professional was evaluated during the follow-up. To examine recovery, the patients kept diaries during a 6-month period and they were interviewed at 18 months after myocardial infarction. The number of patients with depressive symptoms decreased significantly more in the intervention group compared with the control group during 18 months of follow-up. Distress decreased significantly more among patients under 60 years in the intervention group than in the control group, but the difference was not significant between the groups. No differences in the changes of health-related quality of life were found between the groups during follow-up. However, in the group of patients under 60 years, the improvement of health-related quality of life in the intervention was significantly better in the intervention group compared with the control group during the follow-up. During the follow-up period, there was even a decline in the use of somatic specialized health care services in the intervention group and among intervention patients who had no other long-term disease. Considering recovery experienced by the patients, main categories including many supporting and inhibiting factors and subcategories were identified: clinical and physical, psychological, social, functional and professional category. No differences between the groups were found in satisfaction with information received from the professionals. The brief and easy-to-learn intervention, with which the patients were satisfied, seems to decrease depressive symptoms after myocardial infarction. Interpersonal counselling seems to be beneficial especially with younger patients. These results justify adopting depression screening and interpersonal counselling as part of routine care after myocardial infarction. The first stage evaluation of the use of health care services is interesting, and calls for more studies. From the perspective of individual patients, recovery after myocardial infarction seems to consist of many supporting and inhibiting factors. This is something that is important to take into account in developing nursing practice. The results indicate a need for further studies in outcomes of interpersonal counselling and recovery experienced by the patients after myocardial infarction. In addition, the results encourage widening the research perspective to nursing administration and educational level.

Translational models of coronary artery disease, myocardial infarction and heart failure. Development, validation and in vivo imaging studies using positron emission tomography

Coronary artery disease is an atherosclerotic disease, which leads to narrowing of coronary arteries, deteriorated myocardial blood flow and myocardial ischaemia. In acute myocardial infarction, a prolonged period of myocardial ischaemia leads to myocardial necrosis. Necrotic myocardium is replaced with scar tissue. Myocardial infarction results in various changes in cardiac structure and function over time that results in “adverse remodelling”. This remodelling may result in a progressive worsening of cardiac function and development of chronic heart failure. In this thesis, we developed and validated three different large animal models of coronary artery disease, myocardial ischaemia and infarction for translational studies. In the first study the coronary artery disease model had both induced diabetes and hypercholesterolemia. In the second study myocardial ischaemia and infarction were caused by a surgical method and in the third study by catheterisation. For model characterisation, we used non-invasive positron emission tomography (PET) methods for measurement of myocardial perfusion, oxidative metabolism and glucose utilisation. Additionally, cardiac function was measured by echocardiography and computed tomography. To study the metabolic changes that occur during atherosclerosis, a hypercholesterolemic and diabetic model was used with [18F] fluorodeoxyglucose ([18F]FDG) PET-imaging technology. Coronary occlusion models were used to evaluate metabolic and structural changes in the heart and the cardioprotective effects of levosimendan during post-infarction cardiac remodelling. Large animal models were used in testing of novel radiopharmaceuticals for myocardial perfusion imaging. In the coronary artery disease model, we observed atherosclerotic lesions that were associated with focally increased [18F]FDG uptake. In heart failure models, chronic myocardial infarction led to the worsening of systolic function, cardiac remodelling and decreased efficiency of cardiac pumping function. Levosimendan therapy reduced post-infarction myocardial infarct size and improved cardiac function. The novel 68Ga-labeled radiopharmaceuticals tested in this study were not successful for the determination of myocardial blood flow. In conclusion, diabetes and hypercholesterolemia lead to the development of early phase atherosclerotic lesions. Coronary artery occlusion produced considerable myocardial ischaemia and later infarction following myocardial remodelling. The experimental models evaluated in these studies will enable further studies concerning disease mechanisms, new radiopharmaceuticals and interventions in coronary artery disease and heart failure.

Cardiac Imaging in the Diagnosis of Coronary Artery Disease: The Value of Quantitative Imaging of Myocardial Perfusion and Deformation

Atherosclerosis is a chronic and progressive disease of the vasculature. Increasing coronary atherosclerosis can lead to obstructive coronary artery disease (CAD) or myocardial infarction. Computed tomography angiography (CTA) allows noninvasive assessment of coronary anatomy and quantitation of atherosclerotic burden. Myocardial blood flow (MBF) can be accurately measured in absolute terms (mL/g/min) by positron emission tomography (PET) with [15O] H O as a radiotracer. We studied the coronary microvascular dysfunction as a risk factor for future coronary calcification in healthy young men by measuring the coronary flow reserve (CFR) which is the ratio between resting and hyperemic MBF. Impaired vasodilator function was not linked with accelerated atherosclerosis 11 years later. Currently, there is a global interest in quantitative PET perfusion imaging. We established optimal thresholds of [15O] H O PET perfusion for diagnosis of CAD (hyperemic MBF of 2.3 mL/g/min and CFR of 2.5) in the first multicenter study of this type (Turku, Amsterdam and Uppsala). In myocardial bridging a segment of the coronary artery travels inside the myocardium and can be seen as intramural course (CTA) or systolic compression (invasive coronary angiography). Myocardial bridging is frequently linked with proximal atherosclerotic plaques. We used quantitative [15O] H O PET perfusion to evaluate the hemodynamic effects of myocardial bridging. Myocardial bridging was not associated with decreased absolute MBF or increased atherosclerotic burden. Speckle tracking allows quantitative echocardiographic imaging of myocardial deformation. Speckle tracking during dobutamine stress echocardiography was feasible and comparable to subjective wall motion analysis in the diagnosis of CAD. In addition, it correctly risk stratified patients with multivessel disease and extensive ischemia.