Lüscher, Thomas F.

Abstract The development of novel, non-invasive techniques and standardization of protocols to assess microvascular dysfunction have elucidated the key role of microvascular changes in the evolution of cardiovascular (CV) damage, and their capacity to predict an increased risk of adverse events. These technical advances parallel with the development of novel biological assays that enabled the ex vivo identification of pathways promoting microvascular dysfunction, providing novel potential treatment targets for preventing cerebral-CV disease. In this article, we provide an update of diagnostic testing strategies to detect and characterize microvascular dysfunction and suggestions on how to standardize and maximize the information obtained from each microvascular assay. We examine emerging data highlighting the significance of microvascular dysfunction in the development CV disease manifestations. Finally, we summarize the pathophysiology of microvascular dysfunction emphasizing the role of oxidative stress and its regulation by epigenetic mechanisms, which might represent potential targets for novel interventions beyond conventional approaches, representing a new frontier in CV disease reduction.

Abstract Despite advanced understanding of the biology of atherosclerosis, coronary heart disease remains the leading cause of death worldwide. Progress has been challenging as half of the individuals who suffer sudden cardiac death do not experience premonitory symptoms. Furthermore, it is well-recognized that also a plaque that does not cause a haemodynamically significant stenosis can trigger a sudden cardiac event, yet the majority of ruptured or eroded plaques remain clinically silent. In the past 30 years since the term ‘vulnerable plaque’ was introduced, there have been major advances in the understanding of plaque pathogenesis and pathophysiology, shifting from pursuing features of ‘vulnerability’ of a specific lesion to the more comprehensive goal of identifying patient ‘cardiovascular vulnerability’. It has been also recognized that aside a thin-capped, lipid-rich plaque associated with plaque rupture, acute coronary syndromes (ACS) are also caused by plaque erosion underlying between 25% and 60% of ACS nowadays, by calcified nodule or by functional coronary alterations. While there have been advances in preventive strategies and in pharmacotherapy, with improved agents to reduce cholesterol, thrombosis, and inflammation, events continue to occur in patients receiving optimal medical treatment. Although at present the positive predictive value of imaging precursors of the culprit plaques remains too low for clinical relevance, improving coronary plaque imaging may be instrumental in guiding pharmacotherapy intensity and could facilitate optimal allocation of novel, more aggressive, and costly treatment strategies. Recent technical and diagnostic advances justify continuation of interdisciplinary research efforts to improve cardiovascular prognosis by both systemic and ‘local’ diagnostics and therapies. The present state-of-the-art document aims to present and critically appraise the latest evidence, developments, and future perspectives in detection, prevention, and treatment of ‘high-risk’ plaques occurring in ‘vulnerable’ patients.

Abstract Aims Takotsubo syndrome (TTS) is an acute heart failure syndrome, which shares many features with acute coronary syndrome (ACS). Although TTS was initially described with angiographically normal coronary arteries, smaller studies recently indicated a potential coexistence of coronary artery disease (CAD) in TTS patients. This study aimed to determine the coexistence, features, and prognostic role of CAD in a large cohort of patients with TTS. Methods and results Coronary anatomy and CAD were studied in patients diagnosed with TTS. Inclusion criteria were compliance with the International Takotsubo Diagnostic Criteria for TTS, and availability of original coronary angiographies with ventriculography performed during the acute phase. Exclusion criteria were missing views, poor quality of angiography loops, and angiography without ventriculography. A total of 1016 TTS patients were studied. Of those, 23.0% had obstructive CAD, 41.2% had non-obstructive CAD, and 35.7% had angiographically normal coronary arteries. A total of 47 patients (4.6%) underwent percutaneous coronary intervention, and 3 patients had acute and 8 had chronic coronary artery occlusion concomitant with TTS, respectively. The presence of CAD was associated with increased incidence of shock, ventilation, and death from any cause. After adjusting for confounders, the presence of obstructive CAD was associated with mortality at 30 days. Takotsubo syndrome patients with obstructive CAD were at comparable risk for shock and death and nearly at twice the risk for ventilation compared to an age- and sex-matched ACS cohort. Conclusions Coronary artery disease frequently coexists in TTS patients, presents with the whole spectrum of coronary pathology including acute coronary occlusion, and is associated with adverse outcome. Trial registration ClinicalTrials.gov number: NCT01947621.

Abstract Aims The aim of the present study was to investigate the impact of aspirin on prognosis in takotsubo syndrome (TTS). Methods and results Patients from the International Takotsubo (InterTAK) Registry were categorized into two groups based on aspirin prescription at discharge. A comparison of clinical outcomes between groups was performed using an adjusted analysis with propensity score (PS) stratification; results from the unadjusted analysis were also reported to note the effect of the PS adjustment. Major adverse cardiac and cerebrovascular events (MACCE: a composite of death, myocardial infarction, TTS recurrence, stroke or transient ischaemic attack) were assessed at 30-day and 5-year follow-up. A total of 1533 TTS patients with known status regarding aspirin prescription at discharge were included. According to the adjusted analysis based on PS stratification, aspirin was not associated with a lower hazard of MACCE at 30-day [hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.50–3.04, P = 0.64] or 5-year follow-up (HR 1.11, 95% CI 0.78–1.58, P = 0.58). These results were confirmed by sensitivity analyses performed with alternative PS-based methods, i.e. covariate adjustment and inverse probability of treatment weighting. Conclusion In the present study, no association was found between aspirin use in TTS patients and a reduced risk of MACCE at 30-day and 5-year follow-up. These findings should be confirmed in adequately powered randomized controlled trials. ClinicalTrials.gov Identifier: NCT01947621.

Objective: Takotsubo syndrome (TTS) is characterized by acute left ventricular dysfunction, which can contribute to intraventricular thrombus and embolism. Still, prevalence and clinical impact of thrombus formation and embolic events on outcome of TTS patients remain unclear. This study aimed to investigate clinical features and outcomes of patients with and without intraventricular thrombus or embolism. Additionally, factors associated with thrombus formation or embolism, as well as predictors for mortality, were identified. Approach and Results: TTS patients enrolled in the International Takotsubo Registry at 28 centers in Australia, Europe, and the United States were dichotomized according to the occurrence/absence of intraventricular thrombus or embolism. Patients with intraventricular thrombus or embolism were defined as the ThrombEmb group. Of 1676 TTS patients, 56 (3.3%) patients developed intraventricular thrombus and/or embolism following TTS diagnosis (median time interval, 2.0 days [range, 0–38 days]). Patients in the ThrombEmb group had a different clinical profile including lower left ventricular ejection fraction, higher prevalence of the apical type, elevated levels of troponin and inflammatory markers, and higher prevalence of vascular disease. In a Firth bias-reduced penalized-likelihood logistic regression model apical type, left ventricular ejection fraction ≤30%, previous vascular disease, and a white blood cell count on admission >10×10 3 cells/μL emerged as independent predictors for thrombus formation or embolism. Conclusions: Intraventricular thrombus or embolism occur in 3.3% of patients in the acute phase of TTS. A simple risk score including clinical parameters associated with intraventricular thrombus formation or embolism identifies patients at increased risk. Clinical Trial Registration: URL: http://www.clinicaltrials.gov . Unique identifier: NCT01947621.

Background Left ventricular ( LV ) recovery in takotsubo syndrome ( TTS ) occurs over a wide‐ranging interval, varying from hours to weeks. We sought to investigate the clinical predictors and prognostic impact of recovery time for TTS patients. Methods and Results TTS patients from the International Takotsubo Registry were included in this study. Cut‐off for early LV recovery was determined to be 10 days after the acute event. Multivariable logistic regression was used to assess factors associated with the absence of early recovery. In‐hospital outcomes and 1‐year mortality were compared for patients with versus without early recovery. We analyzed 406 patients with comprehensive and serial imaging data regarding time to recovery. Of these, 191 (47.0%) had early LV recovery and 215 (53.0%) demonstrated late LV improvement. Patients without early recovery were more often male (12.6% versus 5.2%; P =0.011) and presented more frequently with typical TTS (76.3% versus 67.0%, P =0.040). Cardiac and inflammatory markers were higher in patients without early recovery than in those with early recovery. Patients without early recovery showed unfavorable 1‐year outcome compared with patients with early recovery ( P =0.003). On multiple logistic regression, male sex, LV ejection fraction <45%, and acute neurologic disorders were associated with the absence of early recovery. Conclusions TTS patients without early LV recovery have different clinical characteristics and less favorable 1‐year outcome compared with patients with early recovery. The factors associated with the absence of early recovery included male sex, reduced LV ejection fraction, and acute neurologic events. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01947621.

Abstract Background Sports activities may promote arrhythmias in the setting of acute myocarditis. International cardiovascular society recommendations to return to sports activities following acute myocarditis are based on expert consensus in the absence of prospective studies. Purpose We sought to identify patients who may safely resume sports activities 3 months after acute myocarditis. Methods We prospectively enrolled 27 patients with newly diagnosed myocarditis based on clinical parameters, elevated high sensitive troponin (TnT-hs) and cardiac magnetic resonance imaging (CMR) with mildly reduced or preserved LVEF. Follow-up examination included laboratory findings, electrocardiogram (ECG), 48-hour-Holter ECG, echocardiography, exercise stress testing and CMR. Cessation of physical activity was recommended for 3 months. All patients were followed for cardiac events for 12 months. Results Average age was 35 (19–80) years with 73% male patients. All patients performed 3- and 6-month follow-up with above mentioned diagnostic tests. Eight patients did not present for 12-month follow-up, but were contacted by phone. No cardiac events occurred within the interval of 12 months. After 3 months, participants achieved an average of 92% of predicted maximum power on stress test. One case of non-sustained ventricular tachycardia was recorded during 48-hour-Holter ECG. Except for this case, all patients were allowed to resume physical exercise after 3 months. At 6- (n=26) and 12-month (n=19) follow-up no arrhythmias, recurrent myocarditis, worsening left ventricular ejection fraction (LVEF) or physical performance were recorded. TnT-hs, creatine kinase (CK), myoglobin (Mb), and C-reactive protein (CRP) normalized. Conclusion The risk of cardiac events and decreasing LVEF appears to be low after early resumption of exercise in asymptomatic patients who recover from acute myocarditis. Acknowledgement/Funding Forschungskredit of the University of Zurich,the Holcim Foundation, the Hartmann Müller Foundation, and the Walter and Gertrud Siegenthaler Foundation