Low MMP-8/TIMP-1 reflects left ventricle impairment in takotsubo cardiomyopathy and high TIMP-1 may help to differentiate it from acute coronary syndrome.

BACKGROUND: Matrix metalloproteinase 8 (MMP-8) is the most potent type-I collagen protease. Such collagen mainly constitutes the transient fibrosis in takotsubo cardiomyopathy (TTC) endomyocardial biopsies. High MMP-8 and tissue-inhibitor of matrix metalloproteinase-1 (TIMP-1) levels are implicated in acute coronary syndrome (ACS). We compared MMP-8 and TIMP-1 levels in consecutive TTC and ACS patients, and their association to TTC severity. METHODS AND RESULTS: In 45 acute serum samples of TTC, 2072 ACS and 1000 controls, TIMP-1 differed between ACS 146.7ng/mL (115.0-186.3) (median (interquartile range)), TTC 115.7 (94.3-137.7) and controls 80.9 (73.2-90.4), (p<0.0001). MMP-8 levels were similar between ACS and TTC. In receiver-operating characteristics analysis, TIMP-1 differentiated TTC from ACS with an area under the curve (AUC) of 0.679 (p<0.0001) surpassing troponin T (TnT) at 0.522 (p = 0.66). Compared to other differing factors (age, sex, smoking), TIMP-1 improved diagnostic specificity and sensitivity from AUC of 0.821 to 0.844 (p = 0.007). The MMP8/TIMP-1 molar ratio differentiated normal ejection fraction (EF) at 0.27 (0.13-0.51) from decreased EF<50% at 0.08 (0.05-0.20), (p = 0.04) in TTC, but not in ACS. CONCLUSIONS: Even with other differing factors considered, TIMP-1 differentiated TTC from ACS better than TnT. In TTC, the low MMP-8/TIMP-1 molar ratio may reflect decreased proteolysis and increased transient fibrosis, perhaps in part explaining the left-ventricle impairment.

Genetic Risk Scores Predict Recurrence of Acute Coronary Syndrome.

BACKGROUND: Several clinical risk estimation tools have established their role in the prediction of recurrence of acute coronary syndrome (ACS), but the value of genetic risk scores (GRSs) remains unclear. We examined how well 2 different GRSs estimate recurrent ACS and whether clinical factors are associated with GRSs. METHODS AND RESULTS: A cohort of 2090 consecutive patients with ACS who underwent coronary angiography between July 2006 and March 2008 in a single tertiary center was genotyped and prospectively followed up for a median of 5.5 years. We formed 2 partially overlapping GRSs: GRS47 of 47 single-nucleotide polymorphisms with previously reported significant association with coronary artery disease and GRS153 of 153 single-nucleotide polymorphisms with significant or suggestive association with coronary artery disease. GRS47 showed association with recurrent ACS independent of clinical factors (P=0.037; hazard ratio, 1.17; 95% confidence interval, 1.01-1.36). GRS153 had no association with either recurrent ACS or composite of recurrent ACS or death. Also, GRS47 was associated inversely with smoking and ST-segment-elevation myocardial infarction (P=0.004; odds ratio, 0.22; 95% confidence interval, 0.08-0.62 and P=0.041; odds ratio, 0.36; 95% confidence interval, 0.13-0.96, respectively). CONCLUSIONS: GRSs combined of 47 known coronary artery disease risk single-nucleotide polymorphisms were associated with recurrent ACS after multivariable adjustments in a heterogenic ACS population for the first time. Smoking and ST-segment-elevation myocardial infarction had an inverse association with the GRSs. The significance of smoking in relation to genetic coronary artery disease predisposition may merit further evaluation in patients with ACS.

Genetic Variability Overrides the Impact of Parental Cell Type and Determines iPSC Differentiation Potential.

Reports on the retention of somatic cell memory in induced pluripotent stem cells (iPSCs) have complicated the selection of the optimal cell type for the generation of iPSC biobanks. To address this issue we compared transcriptomic, epigenetic, and differentiation propensities of genetically matched human iPSCs derived from fibroblasts and blood, two tissues of the most practical relevance for biobanking. Our results show that iPSC lines derived from the same donor are highly similar to each other. However, genetic variation imparts a donor-specific expression and methylation profile in reprogrammed cells that leads to variable functional capacities of iPSC lines. Our results suggest that integration-free, bona fide iPSC lines from fibroblasts and blood can be combined in repositories to form biobanks. Due to the impact of genetic variation on iPSC differentiation, biobanks should contain cells from large numbers of donors.

Differences in ST-elevation and T-wave amplitudes do not reliably differentiate takotsubo cardiomyopathy from acute anterior myocardial infarction.

BACKGROUND: Previous efforts to distinguish acute anterior ST-elevation myocardial infarction (anterior-STEMI) from various forms of takotsubo cardiomyopathy (TTC) by electrocardiography (ECG) have produced differing results. METHODS: We performed a retrospective comparison of acute ECGs between 48 apical and 9 mid-ventricular TTC patients, with 96 anterior-STEMI patients. ECG was recorded in acute phase (<24h from onset of pain), and analyzed for ST-changes, negative T-waves, abnormal Q-waves and QT-interval duration. Time from onset of pain to ECG was gathered from patient records. RESULTS: Anterior-STEMI patients had ST-elevation in lead V1 more frequently than apical (70% vs 15%, p<0.0001) or mid-ventricular TTC patients (70% vs 0%, p<0.0001), and higher ST-elevation amplitudes in leads V2-V5 (p<0.02). Lack of ST-elevation in lead V1 and ST-elevation amplitude <2mm in lead V2 distinguished TTC from anterior-STEMI patients with 63% sensitivity and 93% specificity, with 79% predictive value. CONCLUSIONS: In patients with anterior ST-elevation and acute chest pain, lack of ST-elevation in lead V1 and ST-elevation amplitude <2mm in lead V2 suggests a TTC diagnosis. However, this criterion is not reliable enough in clinical practice to distinguish between TTC and anterior-STEMI patients.

[Takotsubo cardiomyopathy]. / Takotsubokardiomyopatia.

Takotsubo cardiomyopathy resembles cardiac infarction in its clinical picture, but without the presence of coronary artery stenosis. Most patients are postmenpausal women. Dysfunction of the autonomic nervous system and an excess of catecholamines - most likely adrenaline - are considered to be the cause of the syndrome. A contrast examination is essential to exclude coronary artery disease, and it will actually reveal a motion disturbance typical of takotsubo cardiomyopathy. Beta blocker medication is preserved, although it will not completely protect form relapse. The prognosis is good, and the cardiac motion disturbance usually recedes in 4 to 6 weeks.

Mortality rate increases steeply with nonadherence to statin therapy in patients with acute coronary syndrome.

BACKGROUND: In a prospective cohort of consecutive acute coronary syndrome (ACS) patients, we compared the adherence rate of statin usage and mortality rate during a median follow-up of 23 months. HYPOTHESIS: Adherence to statin therapy after acute coronary syndrome affects mortality rate. METHODS: We analyzed ACS patients (N = 1969; age, 65.9 ± 11.8 years; female 30.4%) who underwent angiography between March 2006 and March 2008. The postdischarge usage of statins was based on the purchase register of the Social Insurance Institution of Finland. The death rate was verified from Statistics Finland. RESULTS: At discharge, the rate of statin prescription to patients was 95.4% (n = 1878). When comparing adherent patients (n = 1200; 61.7%), who purchased the medication systematically until the end of the median 23-month follow-up, with nonadherent patients (n = 94; 4.8%), who did not use the medication at all, there was a vast difference in absolute death rate between the groups: 4.9% vs 14.9%, respectively (P < 0.001). We conducted Cox proportional hazards model with ACS type, cerebrovascular attack, diabetes, age, 3-artery disease, and cancer as adjusted confounders. Compared with regular statin users, nonusers were associated with a >2× increased hazard ratio of mortality (hazard ratio: 2.70, 95% confidence interval: 1.49-4.90, P = 0.001). CONCLUSIONS: Statin medication is essential for discharged ACS patients. They should be strongly encouraged to purchase and use it.