Pericardial Involvement in ST-Segment Elevation Myocardial Infarction as Detected by Cardiac MRI.

Background: Post myocardial infarction pericarditis is considered relatively rare in the current reperfusion era. The true incidence of pericardial involvement may be underestimated since the diagnosis is usually based on clinical and echocardiographic parameters. Objectives: This study aims to document the incidence, extent, and prognostic implication of pericardial involvement in ST-segment elevation myocardial infarction (PISTEMI) using cardiac MRI (CMR). Methods: One hundred and eighty-seven consecutive ST-segment elevation myocardial infarction patients underwent CMR on day 5 ± 1 following admission, including steady-state free precession (SSFP) and late Gadolinium enhancement (LGE) sequences. Late Gadolinium enhancement and microvascular obstruction (MVO) were quantified as a percentage of left ventricular (LV) mass. Late Gadolinium enhancement was graded for transmurality according to the 17 AHA left ventricle (LV) segment model (LGE score). Late pericardial enhancement (LPE), the CMR evidence of pericardial involvement, was defined as enhanced pericardium in the LGE series and was retrospectively recorded as present or absent according to the 17 AHA segments. Late pericardial enhancement was evaluated adjacent to the LV, the right ventricle, and both atria. Clinical, laboratory, angiographic, and echocardiographic data were collected. Clinical follow-up for major adverse cardiac events (MACE) was documented and correlated with CMR indices, including LGE, MVO, and LPE. Results: Late pericardial enhancement (LPE+) was documented in 77.5% of the study cohort. A strong association was found between LPE and the degree and extent of myocardial injury (LGE, MVO). Both LGE and MVO were significantly correlated with increased MACE on follow-up. On the contrary, LPE presence, either adjacent to the LV or the other cardiac chambers, was associated with a lower MACE rate in a median of 3 years of follow-up HR 0.39, 95% CI (0.21-0.7), p = 0.002, and HR 0.48, 95% CI (0.26-0.9), p = 0.02, respectively. Conclusions: Prognostic implication of pericardial involvement in ST-segment elevation myocardial infarction was documented by CMR in 77.5% of our STEMI cohort. Late pericardial enhancement presence correlated significantly with the extent and severity of the myocardial damage. Unexpectedly, it was associated with a considerably lower MACE rate in the follow-up period.

Post-ST-Segment-Elevation Myocardial Infarction Platelet Reactivity Is Associated With the Extent of Microvascular Obstruction and Infarct Size as Determined by Cardiac Magnetic Resonance Imaging.

Background Despite optimized medical management and techniques of primary percutaneous coronary intervention, a substantial proportion of patients with ST-segment-elevation myocardial infarction (STEMI) display significant microvascular damage. Thrombotic microvascular obstruction (MVO) has been implicated in the pathogenesis of microvascular and subsequent myocardial damage attributed to distal embolization and microvascular platelet plugging. However, there are only scarce data regarding the effect of platelet reactivity on MVO. Methods and Results We prospectively evaluated 105 patients in 2 distinct periods (2012-2013 and 2016-2018) who presented with first ST-segment-elevation myocardial infarction and underwent primary percutaneous coronary intervention. All patients were treated with dual antiplatelet therapy (DAPT). Blood samples were analyzed for platelet reactivity, and cardiac magnetic resonance imaging scans were evaluated for late gadolinium enhancement and MVO. DAPT suboptimal response was defined as hyporesponsiveness to either aspirin or P2Y12 receptor inhibitor agents and demonstrated in 31 patients (29.5%) of the current cohort. Suboptimal platelet response to DAPT was associated with a significantly greater extent of MVO when expressed as a percentage of the left ventricular mass, left ventricular scar, and the number of myocardial left ventricular segments showing MVO (P<0.01 for each). Adjusted multivariable logistic regression model revealed that suboptimal response to DAPT is significantly associated with both greater late gadolinium enhancement (P<0.01) and MVO extent (odds ratio, 3.7 [95% CI, 1.3-10.5]; P=0.01). Patients with a greater extent of MVO were more likely to sustain major adverse cardiovascular events at a 1-year follow-up (37% versus 11%; P<0.01). Conclusions In patients undergoing primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction, platelet reactivity in response to DAPT is a key predictor of the extent of both myocardial and microvascular damage.

Sex-Based Differences in Characteristics and In-Hospital Outcomes among Patients With Diagnosed Acute Myocarditis.

Data are scarce regarding sex differences among patients with acute myocarditis (AM). Our aim was to define the sex differences in clinical characteristics as well as in-hospital outcomes in a cohort of consecutive patients hospitalized due to AM. We analyzed data of 322 consecutive patients from January 2005 to December 2017 who were hospitalized with the diagnosis of AM. Eighty-four percent (N = 272) of the patients were males. When compared to females, male patients were younger (36 ± 14 vs 45 ± 17 years, p <0.001), more likely to present with ST segment elevation (75% vs 44%. p <0.001) as well as PR depression upon ECG, and have higher admission troponin levels (7.6 ± 11 vs 2.3 ± 4 µg/L, p <0.001). Moreover, males were more likely to have late gadolinium enhancement upon cardiac magnetic resonance. While male patients were more likely to have ventricular arrhythmias during hospitalization (7% vs 0%, p = 0.05), there were no differences in the incidence of in-hospital mortality or the need for escalation therapy during hospitalization between both groups. There were no episodes of mortality upon all patients among a follow-up of 1 year. In conclusion, male patients, which constitute the majority of patients admitted with AM were younger, more likely to present with ST elevation, had higher troponin levels at admission, and had a higher rate of ventricular arrhythmias compared to females. There were no differences in post-discharge mortality rates between males and females.

Epidemiology Characteristics and Outcome of Patients With Clinically Diagnosed Acute Myocarditis.

BACKGROUND: There are controversial data regarding the outcome and management of patients hospitalized with clinically diagnosed acute myocarditis. METHODS: We retrospectively evaluated data of 322 consecutive patients admitted to the Sheba Medical Center with clinically suspected acute myocarditis from January 2005 to December 2017. Patients were subdivided into 2 groups based on their left ventricular ejection fraction (LVEF) at presentation: 1) patients with an LVEF <50% (n = 60) and 2) patients with an LVEF ≥50% (n = 260). We aimed to evaluate the clinical characteristics, management, and in-hospital outcome as well as short-term and 1-year outcome of patients admitted with acute myocarditis. RESULTS: The mean age of the study population was 37 ± 14 years, most of them (84%) males. Although chest pain was the main complaint in 89% of the patients at presentation, only 35% had typical pericardial pain. Patients with a LVEF <50% were more likely to demonstrate ST depression or T wave inversion on their electrocardiogram (ECG) at presentation (33% vs 18%, P = 0.007), and have higher levels of admission and peak troponin compared to those with LVEF ≥50%,(12.7 µ/L ± 15 µ/L vs 5.5 µ/L ± 9.2 µ/L, P = 0.001 for admission troponin, 18.8 µ/L ± 19.9 µ/L vs 8.4 µ/L ± 11.6 µ/L, P <0.001, for peak troponin). Univariate analysis showed that patients with an LVEF <50% were more likely to suffer from adverse cardiovascular events, defined as a composite of the following: 1) acute decompensated congestive heart failure; 2) ventricular arrhythmias; and 3) in-hospital mortality, compared to those with an LVEF ≥50% (15 [25%] vs10 [4%], P <0.001). Consistently, multivariable analysis showed that patients with an LVEF <50% had a 4-fold increased risk of adverse cardiovascular events compared to those patients with an LVEF ≥50% (heart rate [HR] = 4.30; 95% confidence interval [CI] 1.59-11.49; P <0.001). CONCLUSIONS: Patients with clinical acute myocarditis seem to have an overall good prognosis. Although patients with an LVEF <50% are at a higher risk of in-hospital adverse events compared to those with an LVEF ≥50%, this propensity is not reflected during 1-year of follow-up.