1Friedrich-Alexander-Universität Erlangen-Nürnberg Medizinische Klinik 2 - Kardiologie und Angiologie Erlangen, Deutschland
Background
During the routine diagnostic workup of patients with suspected non-ST-segment elevation myocardial infarction (NSTEMI), transthoracic echocardiography (TTE) is indicated to identify regional wall motion abnormalities (RWMA). This study aims to analyze diagnostic and prognostic implications of RWMA in NSTEMI patients.
Methods
NSTEMI patients transferred to the cardiac catheterization laboratory were prospectively included in a single-center, all-comers, real-world registry containing data on baseline characteristics, diagnostic workup, coronary angiography and revascularization, as well as in-hospital outcome. RWMA were classified as apical, apical inferior, apical lateral, anterior, anterolateral, anteroseptal, inferolateral, and inferior or inferoseptal. Global hypokinesia was not classified as RWMA. RWMA were considered as matching the territory of the culprit lesion if present in at least one of the corresponding segments and as inconsistent with angiographic findings in the absence of a culprit lesion.
Results
A total of 920 consecutive patients with NSTEMI and TTE information on RWMA were analyzed (mean age 70 [60-79], 69.5% male). RWMA were present in 69.1% of these patients. More specifically, RWMA were present apical in 35.7%, apical inferior in 14.3%, apical lateral in 12.6%, anterior in 8.0%, anterolateral in 11.7%, anteroseptal in 16.1%, inferolateral in 23.9%, and inferior or inferoseptal in 26.5% of patients, respectively.
While there was no difference in the frequency of chest pain, patients with RWMA were more likely to experience dyspnea (42.5 vs. 34.2%, p=0.021). These patients also showed higher peak levels of troponin (175 [37.0-721] vs. 108 [16.9-309] x ULN, p<0.001) and creatine kinase (417 [208-917] vs. 288 [162-542] U/l, p=0.001). RWMA were associated with a higher incidence of ischemic ECG changes (53.9 vs. 33.8%, p<0.001) and lower ejection fraction (45 [35-50] vs. 55 [55-60] %, p<0.001). Culprit lesions of patients with RWMA had a higher maximum diameter stenosis (99 [90-100] vs. 95 [90-99] %, p<0.001) and were more often totally occluded (28.2 vs. 15.0%, p<0.001). The rate of type 2 myocardial infarction was significantly higher for patients presenting without RWMA (25.4 vs. 16.7%, p=0.003). RWMA were associated with a higher incidence of in-hospital complications (17.0 vs. 10.2%, OR 1.80 [1.18-2.83]) defined as the composite of in-hospital death (6.6 vs. 3.9%, OR 1.75 [0.92-3.63]), cardiogenic shock on presentation (8.5 vs. 3.5%, OR 2.54 [1.33-5.37]) or in the further clinical course (13.1 vs. 8.1%, OR 1.70 [1.07-2.82]), the need for mechanical ventilation (9.9 vs. 7.0%, OR 1.45 [0.87-2.51]), or ventricular rupture (0.2 vs. 0.0%, p=1.0).
In patients with an identifiable culprit lesion, 71.3% showed RWMA. RWMA did not occur more frequently with any specific culprit vessel (p=0.168). RWMA matched the vessel territory in 87.0% for LAD, in 92.2% for LCX, in 84.0% for RCA, and in 100% for LM culprit lesions, and in 100% for multiple culprit vessels as well. Among patients with a RWMA, the territory corresponded to a culprit lesion in 74.5%, while in 16.5% of these patients no culprit lesion was identifiable.
Conclusions
In this all-comers, real-world registry, the presence of echocardiographic RWMA was associated with a significantly higher incidence of in-hospital complications in patients with NSTEMI. If RWMA were present, they matched the territory of the culprit vessel in about ¾ of patients.