Left Ventricular Hypertrophy Is Associated With Increased Infarct Size and Decreased Myocardial Salvage in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention.

Approximately one third of patients with ST-segment elevation myocardial infarction (STEMI) have left ventricular hypertrophy (LVH), which is associated with impaired outcome. However, the causal association between LVH and outcome in STEMI is unknown. We evaluated the association between LVH and: myocardial infarct size, area at risk, myocardial salvage, microvascular obstruction, left ventricular (LV) function (all determined by cardiac magnetic resonance [CMR]), and all-cause mortality and readmission for heart failure in STEMI patients treated with primary percutaneous coronary intervention. In this substudy of the DANAMI-3 trial, 764 patients underwent CMR. LVH was defined by CMR and considered present if LV mass exceeded 77 (men) and 67 g/m2 (women). One hundred seventy-eight patients (24%) had LVH. LVH was associated with a larger final infarct size (15% [interquartile range {IQR}, 10-21] vs 9% [IQR, 3-17]; P<0.001) and smaller final myocardial salvage index (0.6 [IQR, 0.5-0.7] vs 0.7 [IQR, 0.5-0.9]; P<0.001). The LVH group had a higher incidence of microvascular obstruction (66% vs 45%; P<0.001) and lower final LV ejection fraction (LVEF; 53% [IQR, 47-60] vs 61% [IQR, 55-65]; P<0.001). In a Cox regression analysis, LVH was associated with a higher risk of all-cause mortality and readmission for heart failure (hazard ratio 2.59 [95% CI, 1.38-4.90], P=0.003). The results remained statistically significant in multivariable models. LVH is independently associated with larger infarct size, less myocardial salvage, higher incidence of microvascular obstruction, lower LVEF, and a higher risk of all-cause mortality and incidence of heart failure in STEMI patients treated with primary percutaneous coronary intervention. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01435408.

Nepper-Christensen L ，Lønborg J ，Ahtarovski KA ，Høfsten DE ，Kyhl K ，Ghotbi AA ，Schoos MM ，Göransson C ，Bertelsen L ，Køber L ，Helqvist S ，Pedersen F ，Saünamaki K ，Jørgensen E ，Kelbæk H ，Holmvang L ，Vejlstrup N ，Engstrøm T ... -  《Journal of the American Heart Association》

Impact of left ventricular hypertrophy on myocardial injury in patients with ST-segment elevation myocardial infarction.

Stiermaier T ，Pöss J ，Eitel C ，de Waha S ，Fuernau G ，Desch S ，Thiele H ，Eitel I ... -  《-》

Myocardial Damage in Patients With Deferred Stenting After STEMI: A DANAMI-3-DEFER Substudy.

Although some studies found improved coronary flow and myocardial salvage when stent implantation was deferred, the DANAMI-3-DEFER (Third DANish Study of Optimal Acute Treatment of Patients With ST-elevation Myocardial Infarction) did not show any improvement in clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) and deferred stenting. This study sought to evaluate the effect of deferred stent implantation on infarct size, myocardial salvage, and microvascular obstruction (MVO) in patients with STEMI. In the present DANAMI-3 substudy, a total of 510 patients with STEMI were randomized to PCI with deferred versus immediate stent implantation. The patients underwent a cardiac magnetic resonance examination before discharge after the index procedure and again 3 months later. The primary endpoint was final infarct size. Deferred stenting did not reduce final infarct size (9% left ventricle [LV]; interquartile range [IQR]: 3% to 18% vs. 10% LV; IQR: 3% to 18%; p = 0.67). Similarly, deferred stenting was not associated with myocardial salvage index (66%; IQR: 50% to 89% vs. 67%; IQR: 49% to 88%; p = 0.80) or presence of MVO (43% vs. 42%; p = 0.78). In a post hoc analysis, stent length was the only subgroup of 7 that had an effect on outcome. In patients with a stent length ≥24 mm, deferred stenting reduced the final infarct size (6% LV; IQR: 2% to 18% vs. 13% LV; IQR: 7% to 23%; p = 0.006; and p for interaction = 0.005). In the DANAMI-3-DEFER cardiac magnetic resonance substudy, routine deferred stenting did not reduce infarct size or MVO and did not increase myocardial salvage. These results do not support the use of routine deferred stenting in STEMI patients treated with primary PCI. (DANish Study of Optimal Acute Treatment of Patients With ST-elevation Myocardial Infarction [DANAMI-3]; NCT01435408).

Lønborg J ，Engstrøm T ，Ahtarovski KA ，Nepper-Christensen L ，Helqvist S ，Vejlstrup N ，Kyhl K ，Schoos MM ，Ghotbi A ，Göransson C ，Bertelsen L ，Holmvang L ，Pedersen F ，Jørgensen E ，Saunamäki K ，Clemmensen P ，De Backer O ，Kløvgaard L ，Høfsten DE ，Køber L ，Kelbæk H ，DANAMI-3 Investigators ... -  《-》

Impact of Atrial Fibrillation During ST-Segment-Elevation Myocardial Infarction on Infarct Characteristics and Prognosis.

Atrial fibrillation (AF) is frequently observed in patients with ST-segment-elevation myocardial infarction and associated with worse clinical outcome. However, the mechanisms for this increased risk are not fully understood. The purpose of this study was to investigate the relationship of the presence of AF to cardiac magnetic resonance (CMR) derived myocardial salvage and damage as well as clinical outcomes. This multicenter CMR study enrolled 786 patients with ST-segment-elevation myocardial infarction. CMR parameters (infarct size, myocardial salvage index, microvascular obstruction, and myocardial function) were assessed 3 (interquartile range [IQR], 2-4) days post-ST-segment-elevation myocardial infarction and compared between patients with or without AF during hospitalization. Major adverse cardiac events were assessed as a composite of all-cause death, reinfarction, and new congestive heart failure at 12 months. AF was documented in 48 (6.1%) patients. There was no significant difference in infarct size (18 [IQR, 9-29]% versus 17 [IQR, 9-25]% of left ventricular mass; P=0.340), myocardial salvage index (51 [IQR, 34-69] versus 51 [IQR, 33-69]; P=0.830), or microvascular obstruction (0.6 [IQR, 0-2.0]% versus 0.0 [IQR, 0-1.8]% of left ventricular mass; P=0.340) between groups. Patients with AF had significantly lower left ventricular (47 [IQR, 34-54]% versus 51 [IQR, 44-58]%; P=0.003) and left atrial (42 [IQR, 17-57]% versus 53 [IQR, 45-59]%; P<0.001) ejection fraction. AF was associated with major adverse cardiac events, even when adjusting for clinical risk factors (odds ratio, 2.48 [95% confidence interval, 1.22-5.03]; P=0.0120) or CMR prognosis markers (odds ratio, 3.77 [95% confidence interval, 1.83-7.79]; P=0.001). This CMR study found no major differences in myocardial salvage, infarct size, or microvascular damage in patients with ST-segment-elevation myocardial infarction or without AF. AF was, however, associated with cardiac dysfunction and independently related to major adverse cardiac events. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00712101.

Reinstadler SJ ，Stiermaier T ，Eitel C ，Fuernau G ，Saad M ，Pöss J ，de Waha S ，Mende M ，Desch S ，Metzler B ，Thiele H ，Eitel I ... -  《-》

Prognostic Stratification of Patients With ST-Segment-Elevation Myocardial Infarction (PROSPECT): A Cardiac Magnetic Resonance Study.

Cardiac magnetic resonance (CMR) is a robust tool to evaluate left ventricular ejection fraction (LVEF), myocardial salvage index, microvascular obstruction, and myocardial hemorrhage in patients with ST-segment-elevation myocardial infarction. We evaluated the additional prognostic benefit of a CMR score over standard prognostic stratification with global registry of acute coronary events (GRACE) score and transthoracic echocardiography LVEF measurement. Two hundred nine consecutive patients with ST-segment-elevation myocardial infarction (age, 61.4±11.4 years; 162 men) underwent transthoracic echocardiography and CMR after succesful primary percutaneous coronary intervention. Major adverse cardiac events (MACE) were assessed at a mean follow-up of 2.5±1.2 years. MACE occurred in 24 (12%) patients who at baseline showed higher GRACE risk score (P<0.01), lower LVEF with both transthoracic echocardiography and CMR, lower myocardial salvage index, and higher per-patient myocardial hemorrhage and microvascular obstruction prevalence and amount as compared with patients without MACE (P<0.01). The best cut-off values of transthoracic echocardiography-LVEF, CMR-LVEF, myocardial salvage index, and microvascular obstruction to predict MACE were 46.7%, 37.5%, 0.4, and 2.6% of left ventricular mass, respectively. Accordingly, a weighted CMR score, including the following 4 variables (CMR-LVEF, myocardial salvage index, microvascular obstruction, and myocardial hemorrhage), with a maximum of 17 points was calculated and included in the multivariable analysis showing that only CMR score (hazard ratio, 1.867 per SD increase [1.311-2.658]; P<0.001) was independently associated with MACE with the highest net reclassification improvement as compared to GRACE score and transthoracic echocardiography-LVEF measurement. CMR score provides incremental prognostic stratification as compared with GRACE score and transthoracic echocardiography-LVEF and may impact the management of patients with ST-segment-elevation myocardial infarction.

Pontone G ，Guaricci AI ，Andreini D ，Ferro G ，Guglielmo M ，Baggiano A ，Fusini L ，Muscogiuri G ，Lorenzoni V ，Mushtaq S ，Conte E ，Annoni A ，Formenti A ，Mancini ME ，Carità P ，Verdecchia M ，Pica S ，Fazzari F ，Cosentino N ，Marenzi G ，Rabbat MG ，Agostoni P ，Bartorelli AL ，Pepi M ，Masci PG ... -  《-》