Anterior STEMI associated with decreased strain in remote cardiac myocardium

Subclinical dysfunction of remote myocardium is related to high NT-proBNP and affects global contractility at follow-up, independently of infarct area

Background

In ST-segment elevation myocardial infarction (STEMI), predictors of subclinical dysfunction of remote myocardium are unknown. We prospectively aimed at identifying clinical and biochemical correlates of remote subclinical dysfunction and its impact on left ventricular ejection fraction (LVEF).

Methods

One-hundred thirty-three patients (63.9 ± 12.1 years, 68% male) with first successfully treated (54% anterior, 46% non-anterior, p = 0.19) STEMI underwent echocardiography at 5 ± 2 days after onset and at 8 ± 2-month follow-up, and were compared to 13 age and sex-matched (63.3 ± 11.4) healthy controls. All 16 left ventricular (LV) segments were grouped into ischemic, border, and remote myocardium: mean value of longitudinal strain (LS) within grouped segments were expressed as iLS, bLS, rLS, respectively. LV end-diastolic (EDV), end-systolic (ESV) volumes indexed for body surface area (EDVi, ESVi, respectively), LVEF and global LS (GLS) were determined. Creatinine, glomerular filtration rate, admission level of NT-pro-brain-natriuretic peptide (NT-proBNP) and troponin peaks were considered for the analysis.

Results

At baseline, rLS (15.5 ± 4.4) was better than iLS (12.9 ± 4.8, p < 0.001), but lower than that in controls (19.1 ± 2.7, p < 0.001) and similar to bLS (15 ± 5.4, p = ns), and did not differ between patients with single or multivessel coronary artery disease (CAD). At multivariate regression analysis, only admission NT-proBNP levels but not peak Tn levels independently predicted rLS (β = -0.58, p = 0.001), as well as iLS (β = -0.52, p = 0.001). Both at baseline and at follow-up, rLS correlated to LVEF similarly to iLS and bLS (p < 0.001 for all). Median value of rLS at baseline was 15%: compared to patients with rLS ≥ 15% at baseline, patients with rLS < 15% showed lower LVEF (52.3 ± 9.4 vs. 58.6 ± 7.6, p < 0.001) and GLS (16.3 ± 3.9 vs. 19.9 ± 3.2), and higher EDVi (62.3 ± 19.9 vs. 54 ± 12, p = 0.009) and ESVi (30.6 ± 15.5 vs. 22.3 ± 7.6, p < 0.001) at follow-up.

Conclusion

In optimally treated STEMI, dysfunction of remote myocardium assessed by LS: (1) is predicted by elevated NT-proBNP; (2) could be independent of CAD extent and infarct size; (3) is associated to worse LV morphological and functional indexes at follow-up.

Diagnostic performance of cardiac magnetic resonance segmental myocardial strain for detecting microvascular obstruction and late gadolinium enhancement in patients presenting after a ST-elevation myocardial infarction

Background

Microvascular obstruction (MVO) and Late Gadolinium Enhancement (LGE) assessed in cardiac magnetic resonance (CMR) are associated with adverse outcome in patients with ST-elevation myocardial infarction (STEMI). Our aim was to analyze the diagnostic performance of segmental strain for the detection of MVO and LGE.

Methods

Patients with anterior STEMI, who underwent additional CMR were enrolled in this sub-study of the CARE-AMI trial. Using CMR feature tracking (FT) segmental circumferential peak strain (SCS) was measured and the diagnostic performance of SCS to discriminate MVO and LGE was assessed in a derivation and validation cohort.

Results

Forty-eight STEMI patients (62 ± 12 years old), 39 (81%) males, who underwent CMR (i.e., mean 3.0 ± 1.5 days) after primary percutaneous coronary intervention (PCI) were included. All patients presented with LGE and in 40 (83%) patients, MVO was additionally present. Segments in all patients were visually classified and 146 (19%) segments showed MVO (i.e., LGE+/MVO+), 308 (40%) segments showed LGE and no MVO (i.e., LGE+/MVO–), and 314 (41%) segments showed no LGE (i.e., LGE–). Diagnostic performance of SCS for detecting MVO segments (i.e., LGE+/MVO+ vs. LGE+/MVO–, and LGE–) showed an AUC = 0.764 and SCS cut-off value was –11.2%, resulting in a sensitivity of 78% and a specificity of 67% with a positive predictive value (PPV) of 30% and a negative predictive value (NPV) of 94% when tested in the validation group. For LGE segments (i.e., LGE+/MVO+ and LGE+/MVO– vs. LGE–) AUC = 0.848 and SCS with a cut-off value of –13.8% yielded to a sensitivity of 76%, specificity of 74%, PPV of 81%, and NPV of 70%.

Conclusion

Segmental strain in STEMI patients was associated with good diagnostic performance for detection of MVO+ segments and very good diagnostic performance of LGE+ segments. Segmental strain may be useful as a potential contrast-free surrogate marker to improve early risk stratification in patients after primary PCI.

Comparison of angiographic results and clinical outcomes of no-reflow after stenting in left anterior descending (LAD) versus non-LAD culprit STEMI

Objectives:

No-reflow is a complication that frequently occurs after stenting during primary percutaneous coronary intervention. In this study, we focused on angiographic results and clinical outcomes after no-reflow in the left anterior descending (LAD) artery versus non–left anterior descending artery ST-elevation myocardial infarction (STEMI).

Methods:

In this prospective study, a total of 201 patients who had developed no-reflow during primary percutaneous coronary intervention were enrolled. The patients were divided into left anterior descending artery culprit and non-left anterior descending artery culprit groups. The primary endpoints were final thrombolysis in myocardial infarction flow, corrected thrombolysis in myocardial infarction frame count and final myocardial blush grade. Secondary endpoints were major adverse cardiovascular events in-hospital and at 1 month.

Results:

Out of the 201 patients, 60.19% had culprit left anterior descending artery. Pulse rate, baseline systolic and diastolic blood pressure, single-vessel disease, left ventricular ejection fraction <30%, baseline thrombolysis in myocardial infarction I flow and final thrombolysis in myocardial infarction II flow (24.8% vs 11.3%, p = .017), and thrombolysis in myocardial infarction frame count (28.17 ± 11.86 vs 24.38 ± 9.05, p = .016) were significantly higher in the left anterior descending artery group. In contrast, baseline Killip Class I, three-vessel disease, baseline thrombolysis in myocardial infarction II flow, final thrombolysis in myocardial infarction III flow (74.4% vs 87.5%, p = .024) and left ventricular ejection fraction >40% were significantly greater in the non–left anterior descending artery group. However, for both in-hospital and at 30 days, overall major adverse cardiovascular event was similar in the two groups. The demographics, clinical and medication profiles and the routes used to treat no-reflow were all comparable in both groups.

Conclusions:

No-reflow in left anterior descending artery ST-elevation myocardial infarction is associated with lower final thrombolysis in myocardial infarction III flow, higher thrombolysis in myocardial infarction frame count and relatively lower Grade III myocardial blush than non-left anterior descending artery ST-elevation myocardial infarction with subsequent lower left ventricular ejection fraction and a higher frequency of in-hospital heart failure and hospitalisation due to heart failure.