Myocarditis in Relation to Angiographic Findings in Patients With Provisional Diagnoses of MINOCA

ObjectivesThe aim of this study was to determine the prevalence of myocarditis among patients presenting with myocardial infarction with nonobstructive coronary arteries (MINOCA) in relation to the angiographic severity of nonobstructive coronary artery disease (CAD).BackgroundMINOCA represents about 6% of all cases of acute myocardial infarction. Myocarditis is a diagnosis that may be identified by cardiac magnetic resonance (CMR) imaging in patients with a provisional diagnosis of MINOCA.MethodsA systematic review was performed to identify studies reporting the results of CMR findings in MINOCA patients with nonobstructive CAD or normal coronary arteries. Study-level and individual patient data meta-analyses were performed using fixed- and random-effects methods.ResultsTwenty-seven papers were included, with 2,921 patients with MINOCA; CMR findings were reported in 2,866 (98.1%). Myocarditis prevalence was 34.5% (95% confidence interval [CI]: 27.2% to 42.2%) overall and was numerically higher in studies that defined MINOCA as myocardial infarction with angiographically normal coronary arteries compared with a definition that permitted nonobstructive CAD (45.9% vs. 32.3%; p = 0.16). In a meta-analysis of individual patient data from 9 of the 27 studies, the pooled prevalence of CMR-confirmed myocarditis was greater in patients with angiographically normal coronary arteries than in those with nonobstructive CAD (51% [95% CI: 47% to 56%] vs. 23% [95% CI: 18% to 27%]; p < 0.001). Men and younger patients with MINOCA were more likely to have myocarditis. Angiographically normal coronary arteries were associated with increased odds of myocarditis after adjustment for age and sex (adjusted odds ratio: 2.30; 95% CI: 1.12 to 4.71; p = 0.023).ConclusionsPatients with a provisional diagnosis of MINOCA are more likely to have CMR findings consistent with myocarditis if they have angiographically normal coronary arteries.     

A Noncontrast CMR Risk Score for Long-Term Risk Stratification in Reperfused ST-Segment Elevation Myocardial Infarction

ObjectivesThis study compared the prognostic value of a noncontrast CMR risk score for the composite of all-cause death, nonfatal myocardial infarction, and new congestive heart failure.BackgroundA cardiovascular magnetic resonance (CMR) risk score including left ventricular ejection fraction (LVEF), myocardial infarct (MI) size, and microvascular obstruction (MVO) was recently proposed to risk-stratify patients with ST-segment elevation myocardial infarction (STEMI).MethodsThe Eitel CMR risk score and GRACE (Global Registry of Acute Coronary Events) score were used as a reference (Score 1: acute MI size ≥19% LV, LVEF ≤47%, MVO >1.4% LV and GRACE score). MVO was replaced by intramyocardial hemorrhage (IMH) in Score 2 (acute MI size ≥19% LV, LVEF ≤47%, IMH, and GRACE score). Score 3 included only LVEF ≤45%, IMH, and GRACE score.ResultsThere were 370 patients in the derivation cohort and 234 patients in the validation cohort. In the derivation cohort, the 3 scores performed similarly and better than GRACE score to predict the 1-year composite endpoint with C-statistics of 0.83, 0.83, 0.82, and 0.74, respectively. In the validation cohort, there was good discrimination and calibration of score 3, with a C-statistic of 0.87 and P = 0.71 in a Hosmer-Lemeshow test for goodness of fit, on the 1-year composite outcome. Kaplan-Meier curves for 5-year composite outcome showed that those with LVEF ≤45% (high-risk) and LVEF >45% and IMH (intermediate-risk) had significantly higher cumulative events than those with LVEF >45% and no IMH (low-risk), log-rank tests: P = 0.02 and P = 0.03, respectively. The HR for the high-risk group was 2.3 (95% CI: 1.1-4.7) and for the intermediate-risk group was 2.0 (95% CI: 1.0-3.8), and these remained significant after adjusting for the GRACE score.ConclusionsThis noncontrast CMR risk score has performance comparable to an established risk score, and patients with STEMI could be stratified into low risk (LVEF >45% and no IMH), intermediate risk (LVEF >45% and IMH), and high risk (LVEF ≤45%). (A Trial of Low-dose Adjunctive alTeplase During prIMary PCI [T-TIME]; NCT02257294) (Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction [BHF MR-MI]; NCT02072850)     

Myocardial Hematoma Documented by Transthoracic Echocardiography After Sequential Coronary Artery Stenting

We report the case of a patient who deteriorated suddenly while undergoing endoluminal coronary artery reconstruction with multiple stents to the left anterior descending coronary artery. With the aid of transthoracic echocardiography, a pericardial effusion was noted; however, dissection of the ventricular wall due to a large myocardial hematoma was also identified. Emergency exploration with evacuation of the pericardial blood with coronary artery bypass graft surgery was successfully accomplished. We discuss the possible factors that could have been associated with this unforeseen complication and the potential benefit of transthoracic echocardiography in early recognition.     

Myocardial bridging increases the risk of coronary spasm

BACKGROUND: Myocardial bridging (MB) has been associated with cardiac events. Whether coronary spasm is one factor contributing to those events is unknown. HYPOTHESIS: This study investigated whether the likelihood of coronary spasm is increased in patients with MB. METHODS: A spasm-provocation test was performed by infusing acetylcholine into the left coronary artery in 114 Japanese patients with chest pain. The test result was defined as positive when the diameter of the coronary artery was reduced by > or = 50% and ST-segment changes were documented. Myocardial bridging was defined as a > 15% reduction in coronary arterial diameter during systole after intracoronary injection of nitroglycerin. RESULTS: Myocardial bridging was identified in 41 patients (36%) and was located in the mid-segment of the left anterior descending coronary artery (LAD) in all patients. Patients with MB experienced coronary spasm more frequently than patients without MB (MB+: 73%; MB-: 40%, p = 0.0006). Furthermore, among patients with a positive spasm-provocation test, coronary spasm occurred more frequently in the mid-segment of the LAD in patients with MB than in those without MB (MB+: 73%; MB-: 45%, p = 0.0259). Multivariate regression analysis demonstrated that MB was a predictor of coronary spasm (odds ratio: 3.478, p = 0.0088). CONCLUSIONS: These results suggest that MB increases the risk of coronary spasm and that coronary spasm may be the proximate etiology of cardiac events associated with MB.     

Pitfalls in the echocardiographic diagnosis of intracardiac and extracardiac masses

Transthoracic and transesophageal two-dimensional (2-D) echocardiography remain the procedures of choice for evaluating cardiac mass lesions. Potential errors in diagnosis can be made, however, if the mass lesion's size, shape, mobility, and attachment to other cardiac structures are not clearly delineated. Usually a left atrial myxoma arises from the interatrial septum at the level of the fossa ovalis. Pitfalls in diagnosis occur when the tumor size is very small, or its attachment site is atypical or ill-defined. Atrial thrombi classically reside in an atrial appendage, but can also form in the body of the left atrium. The presence of atrial fibrillation rhythm, enlarged atrial chamber, prosthetic mitral/tricuspid valves, stenotic mitral/tricuspid valves, low cardiac output state, and spontaneous atrial contrast echoes are all features that favor the mass in question being a thrombus. Ventricular thrombi usually occur with poorly functioning ventricles. The diagnosis of ventricular thrombus should be made with great caution if the systolic function is normal, or if the mass has a band or thread-like appearance. A thorough knowledge of normal anatomical variants that can mimic pathological lesions is also important for reaching a correct diagnosis. Last but not least, as in all testing modalities, the patient's clinical picture should be correlated with the echocardiographic findings.     

Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Complex Coronary Artery Disease

ObjectivesThe aim of this study was to compare, in a cohort of patients with complex coronary artery disease (CAD) and severe aortic stenosis (AS), the clinical outcomes associated with transfemoral transcatheter aortic valve replacement (TAVR) (plus percutaneous coronary intervention [PCI]) versus surgical aortic valve replacement (SAVR) (plus coronary artery bypass grafting [CABG]).BackgroundPatients with complex CAD were excluded from the main randomized trials comparing TAVR with SAVR, and no data exist comparing TAVR + PCI vs SAVR + CABG in such patients.MethodsA multicenter study was conducted including consecutive patients with severe AS and complex CAD (SYNTAX [Synergy Between PCI with Taxus and Cardiac Surgery] score >22 or unprotected left main disease). A 1:1 propensity-matched analysis was performed to account for unbalanced covariates. The rates of major adverse cardiac and cerebrovascular events (MACCE), including all-cause mortality, nonprocedural myocardial infarction, need for new coronary revascularization, and stroke, were evaluated.ResultsA total of 800 patients (598 undergoing SAVR + CABG and 202 undergoing transfemoral TAVR + PCI) were included, and after propensity matching, a total of 156 pairs of patients were generated. After a median follow-up period of 3 years (interquartile range: 1-6 years), there were no significant differences between groups for MACCE (HR for transfemoral TAVR vs SAVR: 1.33; 95% CI: 0.89-1.98), all-cause mortality (HR: 1.25; 95% CI: 0.81-1.94), myocardial infarction (HR: 1.16; 95% CI: 0.41-3.27), and stroke (HR: 0.42; 95% CI: 0.13-1.32), but there was a higher rate of new coronary revascularization in the TAVR + PCI group (HR: 5.38; 95% CI: 1.73-16.7).ConclusionsIn patients with severe AS and complex CAD, TAVR + PCI and SAVR + CABG were associated with similar rates of MACCE after a median follow-up period of 3 years, but TAVR + PCI recipients exhibited a higher risk for repeat coronary revascularization. Future trials are warranted.     

心脏交感神经重构与心律失常:新兴领域的当前认识

心脏内交感神经纤维分布十分广泛,近年发现许多心脏疾病伴有交感神经分布、密度改变的现象,并与心律失常发生、疾病预后都有密切的关联。交感神经重构与心肌组织重构、电重构相互影响,可能是心律失常发生的基础。对交感神经重构进行干预可能成为将来新的一个治疗方向。     

Cardiac free wall rupture in acute myocardial infarction: ameliorative effect of coronary reperfusion.

To investigate the pathophysiology of cardiac free wall rupture (cardiac rupture) following acute myocardial infarction (AMI), and to clarify whether reperfusion therapy prevents cardiac rupture, 1,329 cases of AMI (conventional therapy group: 807 cases and reperfusion therapy group: 533 cases) were studied retrospectively. The overall incidence of cardiac rupture was 2.3% (2.7% in the conventional therapy group vs. 1.7% in the reperfusion therapy group). Patients with cardiac rupture were divided into two subgroups according to the time interval from the onset of AMI to cardiac rupture (early rupture less than or equal to 72 h and late rupture greater than or equal to 4 days). The indices of initial evolution of AMI was a significant risk of early cardiac rupture. The reperfusion therapy group showed significantly lower incidence of late rupture (0.4 vs. 1.5% in conventional therapy group; p less than 0.05). The incidence of cardiac rupture in the unsuccessful reperfusion therapy group was higher than that of the successful group (5.9% of 118 cases vs. 0.5% of 404 cases; p less than 0.05). It is concluded that the etiology of cardiac rupture following AMI cannot be explained by any single factor. Early rupture depends on the initial evolution of AMI, and early reperfusion and collateral flow prevent the late onset cardiac rupture.     

Ionic currents and action potentials in rabbit,rat, and guinea pig ventricular myocytes

Summary Distinct differences exist in action potentials and ionic currents between rabbit, rat, and guinea pig ventricular myocytes. Data obtained at room temperature indicate that about half of the rabbit myocytes show prominent phase 1 repolarization and transient outward current. Action potentials in guinea pig ventricular myocytes resemble those from rabbit myocytes not exhibiting phase 1 repolarization; and guinea pig myocytes do not develop transient outward current. Rat ventricular action potentials are significantly shorter than those from rabbit and guinea pig ventricular myocytes. Unlike rabbit and guinea pig myocytes, rat ventricular myocytes also exhibit a prominent phase 1 and lack a well defined plateau phase during repolarization. All rat ventricular myocytes exhibit a transient outward current which can be best fitted by a double exponential relation. There are no significant differences between the amplitude, voltage dependence and inactivation kinetics of the inward calcium currents observed in rabbit, rat and guinea pig. The steady-state current-voltage relations between –120 mV and –20 mV, which mostly represent the inward rectifier potassium current are similar in rabbit and guinea pig. The amplitude of this current is significantly less in rat ventricular myocytes. The outward currents activated upon depolarization to between –10 and +50 mV are different in the three species. Only a negligible, or absent, delayed rectifier outward current has been observed in rabbit and rat; however, a relatively large delayed rectifier current has been found in guinea pig. These large interspecies variations in outward membrane currents help explain the differences in action potential configurations observed in rabbit, rat, and guinea pig.     

Aldosterone-Related Myocardial Extracellular Matrix Expansion in Hypertension in Humans: A Proof-of-Concept Study by Cardiac Magnetic Resonance

ObjectivesThis study sought to assess the respective effects of aldosterone and blood pressure (BP) levels on myocardial fibrosis in humans.BackgroundExperimentally, aldosterone promotes left ventricular (LV) hypertrophy, and interstitial myocardial fibrosis in the presence of high salt intake.MethodsThe study included 20 patients with primary aldosteronism (PA) (high aldosterone and high BP), 20 patients with essential hypertension (HTN) (average aldosterone and high BP), 20 patients with secondary aldosteronism due to Bartter/Gitelman (BG) syndrome (high aldosterone and normal BP), and 20 healthy subjects (HS) (normal aldosterone and normal BP). Participants in each group were of similar age and sex distributions, and asymptomatic. Cardiac magnetic resonance including cine and T1 mapping was performed blind to the study group to quantify global LV mass index, as well as intracellular mass index and extracellular mass index considered as a measure of myocardial fibrosis in vivo.ResultsMedian plasma aldosterone concentration was as follows: PA = 709 pmol/l (interquartile range [IQR]: 430 to 918 pmol/l); HTN = 197 pmol/l (IQR: 121 to 345 pmol/l); BG = 297 pmol/l (IQR: 180 to 428 pmol/l); and HS = 105 pmol/l (IQR: 85 to 227 pmol/l). Systolic BP was as follows: PA = 147 ± 15 mm Hg; HTN = 133 ± 19 mm Hg; BG = 116 ± 9 mm Hg; and HS = 117 ± 12 mm Hg. LV end-diastolic volume showed underloading in BG and overloading in patients with PA (63 ± 13 ml/m² vs. 82 ± 15 ml/m²; p < 0.0001). Intracellular mass index increased with BP across groups (BG: 36 [IQR: 29 to 41]; HS: 40 [IQR: 36 to 46]; HTN: 51 [IQR: 42 to 54]; PA: 50 [IQR: 46 to 67]; p < 0.0001). Extracellular mass index was similar in BG, HS, and HTN (16 [IQR: 12 to 20]; 15 [IQR: 11 to 18]; and 14 [IQR: 12 to 17], respectively) but 30% higher in PA (21 [IQR: 18 to 29]; p < 0.0001) remaining significant after adjustment for mean BP.ConclusionsOnly primary pathological aldosterone excess combined with high BP increased both extracellular myocardial matrix and intracellular mass. Secondary aldosterone excess with normal BP did not affect extracellular myocardial matrix. (Study of Myocardial Interstitial Fibrosis in Hyperaldosteronism; NCT02938910).