Olov Collste

Myocardial infarction with normal coronary arteries is common and associated with normal findings on cardiovascular magnetic resonance imaging: results from the Stockholm Myocardial Infarction with Normal Coronaries study

Myocardial infarction with angiographically normal coronary arteries (MINCA) is an important subtype of myocardial infarction; however, the prevalence, underlying pathophysiology, prognosis and optimal management of this condition are still largely unknown. Cardiovascular magnetic resonance (CMR) imaging has the potential to clarify the underlying pathology in patients with MINCA. The objective of this study was to investigate the diagnostic value of CMR imaging in this group of patients.

A Case-Control Study of Risk Markers and Mortality in Takotsubo Stress Cardiomyopathy

BACKGROUND Takotsubo stress cardiomyopathy (TSC) is a syndrome characterized by transient myocardial dysfunction with unknown etiology. Although recent studies have suggested that the syndrome is associated with comorbidity and has a dismal prognosis, there is a lack of comprehensive data describing the epidemiology and prognosis of TSC. OBJECTIVES This study compared risk markers and mortality in patients with TSC with that of individuals with or without coronary artery disease (CAD). METHODS Patients with TSC and control subjects were identified from the Swedish Coronary Angiography and Angioplasty Register between 2009 and 2013 and linked with the Swedish national patient registry, cause of death registry, prescription drug registry, and education and income registries. RESULTS Patients with TSC were characterized by a low cardiovascular risk factor profile but with increased chronic obstructive pulmonary disease, migraine, and affective disorders. The use of beta-blockers was less common but use of β2-adrenergic agonist agents was more common in patients with TSC compared with either of the control groups. Being a patient with TSC was associated with a hazard ratio of 2.1 for death compared with the control subjects without CAD (95% confidence interval: 1.4 to 3.2). This was similar to the excess mortality risk seen among the CAD control subjects compared with control subjects without CAD (hazard ratio: 2.5; 95% confidence interval: 1.8 to 3.3). These associations remained significant after adjusting for CAD risk factors and risk markers for TSC. CONCLUSIONS The findings of increased risk associated with β2-adrenergic agonist agents together with stress related to affective disorders emphasize the pathogenic role of sympathetic stimulation. The prognosis regarding mortality is worse than in control subjects without CAD and similar to patients with CAD emphasizing the urgent need for studies on optimal treatment of TSC.

Risk factors for myocardial infarction with normal coronary arteries and myocarditis compared with myocardial infarction with coronary artery stenosis.

The interest and awareness of myocardial infarction with normal coronary arteries (MINCA) have increased recently due to the frequent use of coronary angiography, the description of Takotsubo stress cardiomyopathy, and new sensitive troponin analyses. The prevalence of MINCA in all patients with myocardial infarction (MI) was registered during a 3-month period in the Stockholm metropolitan area in Sweden. The results showed that MINCA is more common than previously thought (7%) and affecting one third of every woman with MI. Patients with myocarditis were younger and more often presented with signs of inflammation such as elevated C-reactive protein and fever. Myocarditis constitutes an important differential diagnosis for coronary artery disease. There is a need for larger studies of MINCA, including investigation with cardiac magnetic resonance imaging, to establish prevalence and pathological process in this important subgroup of MI.

Risk Factors and Markers for Acute Myocardial Infarction With Angiographically Normal Coronary Arteries.

Myocardial Infarction with normal coronary arteries (MINCA) is common with a prevalence of 1% to 12% of all myocardial infarctions. The pathogenic mechanisms of MINCA are still unknown, but endothelial dysfunction has been suggested as a possible cause. To investigate risk factors and markers for MINCA, we conducted a case-control study. Considering the reported low prevalence of classical risk factors for coronary heart disease (CHD) in some but not all studies, our hypothesis was that endothelial function and intima-media thickness (IMT) were better, respectively lower, than CHD controls. One hundred patients with MINCA fulfilling diagnostic criteria according to the European Society of Cardiology/American Collage of Cardiology/American Heart Association universal definition of myocardial infarction with myocarditis excluded by cardiac magnetic resonance imaging were investigated. Risk factors, endothelial function (EndoPAT), and IMT were compared to gender- and age-matched patients with myocardial infarction and CHD, respectively healthy controls. Smoking, hypertension, impaired glucose tolerance and diabetes mellitus, inflammatory disease, and psychiatric disorders were more common in patients with MINCA than in healthy controls. In contrast to patients with CHD, the lipid profile was antiatherogenic with low low-density lipoprotein and high high-density lipoprotein cholesterol. There were no major differences between the groups regarding endothelial function and IMT that were in the normal range. In conclusion, the present study showed that MINCA was associated with many established cardiovascular risk factors without major differences in atherosclerosis markers. MINCA patients recalled a high prevalence of emotional stress before admission that together with previous psychiatric vulnerability and female gender speaks strongly in favor of Takotsubo syndrome being an important cause of MINCA.

Coronary flow reserve during dobutamine stress in Takotsubo stress cardiomyopathy

Objectives Takotsubo stress cardiomyopathy (TSC) is an increasingly recognised and diagnosed disease, although the underlying pathophysiology is still unknown. Our aim was to investigate the effect of the catecholamine dobutamine on coronary flow reserve (CFR) measured non-invasively in patients with TSC and controls. Our hypothesis was that dobutamine stress can induce microvascular dysfunction in patients with a previous episode of TSC. Setting This is a case–control study and a substudy of the Stockholm Myocardial Infarction with Normal Coronaries (SMINC) study. Elective dobutamine investigations were performed focusing on non-invasive measurements of CFR. The investigations were performed more than 6 months after the acute event. Participants 22 patients with a previous episode of TSC and 22 sex-matched and age-matched controls were recruited from the SMINC study. All patients with TSC had a previous normal cardiovascular MR investigation. Results CFR at low-dose dobutamine was significantly lower in the TSC group compared with controls, 1.51 and 1.72, respectively (p=0.017). At high-dose dobutamine, CFR was 1.95 and 2.21 in the TSC group and controls, respectively (p=0.098). Conclusions We could not confirm that the catecholamine dobutamine induced microvascular dysfunction in patients with TSC. However, we found a small but significant difference in CFR at low-dose dobutamine, which implies that the role of microvascular function in TSC needs to be further explored.

No myocardial vulnerability to mental stress in Takotsubo stress cardiomyopathy.

Objectives Due to the frequent use of coronary angiography the awareness of Takotsubo stress cardiomyopathy (TSC) has increased although the exact pathophysiology of TSC is still largely unknown. Our objective was to investigate the effects of mental stress on myocardial function, heart rate variability (HRV) and salivary cortisol (SC) in TSC patients. Design This study is a case-control study and a sub-study of the Stockholm Myocardial Infarction with Normal Coronaries (SMINC) study. Setting Mental stress test was performed more than 6 months after the acute event in TSC patients and age- and sex-matched controls. Standard echocardiography and tissue Doppler imaging (TDI) - derived time-phases of cardiac cycle were recorded to calculate myocardial performance index (MPI) to assess ventricular function before and during mental stress. Holter-ECG recording was made to estimate HRV before, during and after mental stress. SC was measured at baseline, before and 20 minutes after mental stress. Subjects Twenty-two TSC patients and 22 sex-and age-matched controls were recruited from the SMINC-study and investigated with a mental stress test. All TSC patients had a previous normal cardiovascular magnetic resonance investigation. Results There were no significant differences at rest or during mental stress for left and right ventricular MPI or other standard diastolic variables between TSC patients and controls. HRV did not differ between TSC patients and controls. There was a trend towards less increase in SC after mental stress in TSC patients compared to controls. Conclusion Mental stress did not induce a significant difference in myocardial function or HRV response between TSC and controls. Moreover, no significant difference could be seen in SC response at baseline, during or after mental stress. This study indicates that myocardial vulnerability to mental stress does not persist in TSC patients.

The value of a new cardiac magnetic resonance imaging protocol in Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA) – a case-control study using historical controls from a previous study with similar inclusion criteria

BackgroundMyocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) is common with a prevalence of 6% of all patients fulfilling the diagnosis of myocardial infarction. MINOCA should be considered a working diagnosis. Cardiac Magnetic Resonance (CMR) imaging has recently been suggested to be of great value to determine the cause behind MINOCA. The objectives of this paper are to describe the rationale behind the second Stockholm Myocardial Infarction with Normal Coronaries (SMINC-2) study and to discuss the protocol for investigation of MINOCA patients in the light of the recently published position paper from the European Society of Cardiology.MethodsThe SMINC-2 study is an open non-randomised study using historical controls for comparison. The primary aim is to prove that MINOCA patients investigated with the latest CMR imaging technique can achieve a diagnosis in 70% of all cases entirely by imaging. By including 150 patients we will have >80% chance to prove that the diagnostic accuracy can be improved by 20 absolute % with a p-value of less than 0.05 when compared with CMR imaging in the SMINC-1 study. Furthermore, in addition to invasive coronary angiography, coronary arteries are evaluated by computed tomography angiography to investigate coronary causes and questionnaires are used to describe Quality-of-Life (QoL). By January 1st 2017, 75 patients have been included.DiscussionWhether CMR imaging can provide a diagnosis to an adequate proportion of MINOCA patients is unknown. Well-defined inclusion and exclusion criteria will be used to compare a MINOCA cohort from the population with an appropriate control group. Positive results are likely to influence future guidelines of the management of MINOCA. Furthermore, the study will give mechanistic insights into MINOCA in particular in patients with “true” myocardial infarction and describe QoL in this vulnerable group of patients.Trial registrationClinical Trials NCT02318498.

Prevalence of anxiety and depression symptoms in patients with myocardial infarction with non-obstructive coronary arteries

BACKGROUND Myocardial infarction with non-obstructive coronary arteries is a working diagnosis for several heart disorders. Previous studies on anxiety and depression in patients with myocardial infarction with non-obstructive coronary arteries are lacking. Our aim was to investigate the prevalence of anxiety and depression among patients with myocardial infarction with non-obstructive coronary arteries. METHODS We included 99 patients with myocardial infarction with non-obstructive coronary arteries together with age- and sex-matched control groups who completed the Beck Depression Inventory and the Hospital Anxiety and Depression Scale (HADS) 3 months after the acute event. RESULTS Using the Beck Depression Inventory, we found that the prevalence of depression in patients with myocardial infarction with non-obstructive coronary arteries (35%) was higher than in healthy controls (9%; P = .006) and similar to that of patients with coronary heart disease (30%; P = .954). Using the HADS anxiety subscale, we found that the prevalence of anxiety in patients with myocardial infarction with non-obstructive coronary arteries (27%) was higher than in healthy controls (9%; P = .002) and similar to that of patients with coronary heart disease (21%; P = .409). Using the HADS depression subscale, we found that the prevalence of depression in patients with myocardial infarction with non-obstructive coronary arteries (17%) was higher than in healthy controls (4%; P = .003) and similar to that of patients with coronary heart disease (13%; P = .466). Patients with myocardial infarction with non-obstructive coronary arteries and takotsubo syndrome scored higher on the HADS anxiety subscale than those without (P = .028). CONCLUSIONS This is the first study on the mental health of patients with myocardial infarction with non-obstructive coronary arteries to show that prevalence rates of anxiety and depression are similar to those in patients with coronary heart disease.