Predictors and implications of Q-waves in ST-elevation acute coronary syndromes

Registry of Acute Myocardial Infarction. REGION-MI - Russian Registry of Acute Myocardial Infarction

Aim      To study features of diagnosis and treatment of acute myocardial infarction (AMI) in Russian hospitals, results of the treatment, and early and late outcomes (6 and 12 months after AMI diagnosis); to evaluate the consistence of the treatment with clinical guidelines; and to evaluate patients' compliance with the treatment.Material and methods  The program was designed for 3 years, including 24 months for recruitment of patients to the study. The study will include 10, 000 patients hospitalized with a confirmed diagnosis (I21 according to ICD-10) of ST segment elevation acute myocardial infarction (MI) (STEMI) or non-ST segment elevation MI (NSTEMI) based on criteria of the European Society of Cardiology Guidelines on Forth Universal Definition of Myocardial Infarction (2018). The follow-up period was divided into three stages: observation during the stay in the hospital and at 6 and 12 months following inclusion into the registry. The primary endpoint included cardiac death, nonfatal MI during the hospitalization and after one-year follow-up. Secondary endpoints were 6-months and one-year incidence of repeated MI, heart failure, ischemic stroke, clinically significant hemorrhage, unscheduled revascularization after discharge from the hospital, and the proportion of patients who continue on statins, antiplatelet drugs, and drugs of other groups for 6 months and 1 year.Results The inclusion of patients into the registry started in 2020 and will continue for 24 months. By the time of the article publication (June, 2021), more than 2,000 patients will be included.Conclusion      REGION-MI (Russian rEGIstry Of acute myocardial iNfarction) is a multicenter, retrospective and prospective observational cohort study that excludes any interference with the clinical practice. Results of the registry will help to analyze a real picture of medical care provided to patients with myocardial infarction and to schedule ways to improve the situation.

LIS-3 Acute Coronary Syndrome Registry: Changes in Clinical and Demographic Characteristics and Tactics of Prehospital and Hospital Treatment of Surviving Patients After Acute Coronary Syndrome Over a 4-Year Period

Aim. To study the changes in clinical and demographic characteristics, risk factors, treatment tactics, the dynamics of drug therapy at the prehospital stage and prescribed during discharge from the cardiology department over a 4-year period in patients after acute coronary syndrome (ACS) with ST segment elevation and ACS without ST segment elevation.

Material and methods. Data from the LIS-3 prospective registry (Lyubertsy mortality study) was used. Patients admitted to the cardiology department of the Lyubertsy district hospital No. 2 for the first 9 months of 2014 (n=104) and for the first 9 months of 2018 (n=223) with a diagnosis of “ACS with ST segment elevation and ACS without ST segment elevation” and with a confirmed diagnosis at discharge “acute myocardial infarction” (AMI) or “unstable angina” (NSA) were included into the study. Comparison of clinical and demographic indicators, risk factors, the frequency of use of acetylsalicylic acid, clopidogrel, statins, beta-blockers, ACE inhibitors, angiotensin II receptor antagonists, anticoagulants at the prehospital stage and during discharge from the hospital were performed.

Results. Significant differences in the gender and age composition of patients were not found. The number of working patients increased. Compared to 2014, in 2018 the number of patients with arterial hypertension increased (64.4% and 75.8%, respectively, p=0.047), and with coronary heart disease decreased significantly (39.4% and 22.4%, respectively, p=0.004), however, the incidence of atrial fibrillation, history of AMI, and cerebral stroke did not change over the period under consideration. The frequency of concomitant diseases did not practically change, except for kidney diseases, which have become more common. A significant decrease in the frequency of thrombolysis and a significant (more than 6-fold) increase in angioplasty with stenting were found. Patients before ACS in 2014 received less antiplatelet agents than in 2018, including dual antiplatelet therapy, ACE inhibitors were prescribed more often. The intake of nitrates decreased, and the use of statins increased (6.7% versus 13.9%, respectively, p>0.05). AMI as the outcome of ACS was almost the same in both men and women. A downward trend in myocardial Q-infarction (p>0.05) was found. Taking dual antiplatelet therapy and ACE inhibitors were more often recommended at discharge and taking nitrates and any diuretics was less common. Statins intake did not change.

Conclusion. The “portrait” of a hospitalized ACS patient changed somewhat over 4 years: the frequency of the history of coronary heart disease significantly decreased, and the frequency of hypertension increased. The presence and significance of risk factors such as hypercholesterolemia and adverse heredity cannot be assessed as before. The frequency of use of antiplatelet agents and statins increased in prehospital therapy; however, in general, a smaller proportion of patients requiring statins took them. The proportion of AMI patients among ACS ones did not change over the study period.

Regression of Q waves and clinical outcomes following primary PCI in anterior STEMI

BACKGROUND

Pathological Q waves are correlated with infarct size, and Q-wave regression is associated with left ventricular ejection fraction improvement. There are limited data regarding the association of Q-wave regression and clinical outcomes. Our main objective was to assess the association of pathological Q wave evolution after reperfusion with clinical outcomes after anterior STEMI.

METHODS

Standard 12-lead electrocardiograms (ECGs) were recorded in 780 anterior STEMI patients treated with primary percutaneous coronary intervention (PCI) from the CIRCUS trial. ECGs were recorded before and 90 min following PCI, as well as at hospitalization discharge and 12 months of follow-up. The number of classic ECG criteria Q waves was scored for each ECG. Patients were classified in the Q wave regression group if they had regression of at least one Q wave between the post-PCI, the discharge and/or one year ECGs. Patients were classified in the Q wave persistent group if they had the same number or greater between the post-PCI, the discharge and/or 1 and one year ECGs. All-cause death and heart failure events were assessed for all patients at one year.

RESULTS

There were 323(43%) patients with persistent Q waves (PQ group), 378(49%) patients with Q wave regression (RQ group) and 60(8%) patients with non-Q wave MI (NQ group). Infarct size as measured by the peak creatine kinase was significantly greater in the PQ group compared to the RQ and NQ groups (4633 ± 2784 IU/l vs. 3814 ± 2595 IU/l vs. 1733 ± 1583 IU/l respectively, p < 0.0001). At one year, there were 22 deaths (7%) in the PQ-group, 15 (4%) in the RQ-group and none in the NQ-group (p = 0.04). There was a 4-fold increase in the risk of death or heart failure in the PQ compared to the NQ group (HR 4.7 [1.1; 19.3]; p = 0.03), but there was no significant difference between NQ and RQ groups (HR 3.3 [0.8; 13.8]; p = 0.09).

CONCLUSION

In a population of anterior STEMI patients, persistent Q waves defined according to the classic ECG criteria after reperfusion was associated with a 4-fold increase in the risk of heart failure or death compared to non-Q-wave MI, while Q-wave regression was associated with significantly lower risk of events.

Comparison of Electrocardiographic Characteristics in Men Versus Women ≤ 55 Years With Acute Myocardial Infarction (a Variation in Recovery: Role of Gender on Outcomes of Young Acute Myocardial Infarction Patients Substudy)

Young women with acute myocardial infarction (AMI) have a worse prognosis than their male counterparts. We searched for differences in the electrocardiographic presentation of men and women in a large, contemporary registry of young adults with AMI that could help explain gender differences in outcomes. The qualifying electrocardiogram was blindly assessed by a central core lab in 3,354 patients (67% women) aged 18 to 55 years included in the Variation in Recovery: Role of Gender on Outcomes of Young AMI Patients study. Compared with men, women did not have a different frequency of sinus rhythm, and they had shorter PR and QRS intervals and longer QTc intervals. Intraventricular conduction disturbances were not different among genders. Notably, women were more likely than men to have abnormal Q waves in anterior leads and a lower frequency of Q waves in other territories. ST-segment elevation myocardial infarction (STEMI) diagnosis was less frequent in women than in men (44.6% vs 55.1%, p < 0.001). Among patients with STEMI, women had less magnitude and extent of ST-segment elevation than men. In patients with non-STEMI, the frequency, magnitude, and extent of ST-segment depression were not different among genders, but women had anterior ST-segment depression less frequently and anterior negative T waves more frequently compared with men. These differences remained statistically significant after adjusting for baseline characteristics. In conclusion, there are significant gender differences in the electrocardiographic presentation of AMI among young patients. Further studies are warranted to evaluate their impact on gender-related differences in the management and outcomes of AMI.

Clinical implications and correlates of Q waves in patients with ST-elevation myocardial infarction treated with fibrinolysis: observations from the CLARITY-TIMI 28 trial

BACKGROUND

The relationships between Q waves that appear during the acute phase of ST-elevation myocardial infarction (STEMI), clinical characteristics, ST-segment resolution (STRes), and clopidogrel therapy in patients treated with fibrinolysis are not well described.

HYPOTHESIS

We hypothesized that Q waves would be associated with less successful reperfusion and increased cardiovascular events.

METHODS

In the CLARITY-TIMI 28 trial, 3491 STEMI patients treated with fibrinolysis were randomized to clopidogrel or placebo. Electrocardiograms were evaluated for STRes post-fibrinolysis and the presence of pathologic Q waves during the index hospitalization in 3322 patients.

RESULTS

Q waves were identified in 2045 patients (61.6%) prior to discharge and were associated with increased odds of congestive heart failure (CHF) (adjusted odds ratio [ORadj ]: 2.10, P = 0.002) or the composite of cardiovascular death/CHF at 30 days (ORadj : 2.08, P ≤ 0.001). Q waves were associated with lower odds of Thrombolysis in Myocardial Infarction [TIMI] flow grade 2 to 3 (ORadj : 0.78, P = 0.028), TIMI myocardial perfusion grade 3 (ORadj : 0.83, P = 0.029), and complete STRes at 90 minutes (ORadj : 0.80, P = 0.030). Patients with both a Q wave and incomplete STRes 90 minutes after fibrinolysis were at higher risk for cardiovascular death or CHF (11.1%) than patients with no Q wave and at least partial STRes (1.9%). Overall, clopidogrel tended to be equally or more effective in patients without Q waves compared to those with Q waves.

CONCLUSIONS

Among STEMI patients treated with fibrinolysis, evaluating for Q waves prior to discharge is a simple method of assessing for less successful reperfusion and an increased risk of adverse 30-day cardiovascular outcomes. The combination of Q waves and 90-minute STRes allows additional risk refinement.

Does silent myocardial infarction add prognostic value in ST-elevation myocardial infarction patients without a history of prior myocardial infarction? Insights from the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) Trial

BACKGROUND

ST-elevation myocardial infarction (STEMI) patients with a prior MI history have worse outcomes. The prognostic significance of silent MI (pathologic Q waves outside the ST-elevation territory) in STEMI is unclear.

METHODS

A total of 5,733 STEMI patients from 296 clinical centers in 17 countries were classified as (1) silent MI-baseline Q waves outside the infarct-related artery territory and no history of prior MI, (2) history of prior MI (HxMI), or (3) no prior MI.

RESULTS

Of 5,733 STEMI patients, 419 (7.3%) had silent MI, 693 (12.1%) had HxMI, and 4,621 (80.6%) had no prior MI. Ninety-day death and death/congestive heart failure/shock were higher in patients with HxMI (8.4% and 15.3%, respectively) and silent MI (6.7% and 13.9%, respectively) compared with patients with no prior MI (4.0% and 9.1%, respectively) (P ≤ .001 for all). After baseline adjustment, patients with HxMI were at increased risk for 90-day death (adjusted hazard ratio [HR] 1.62, 95% CI 1.18-2.21), whereas both those with HxMI and those with silent MI had increased risk of 90-day death/congestive heart failure/shock compared with those with no prior MI (adjusted HR 1.54, 95% CI 1.23-1.93 and adjusted HR 1.46, 95% CI 1.10-1.93, respectively).

CONCLUSIONS

Seven percent of STEMI patients had a silent MI. They represent a novel subgroup at increased risk comparable to those with known prior MI. Hence, in future studies, acquiring baseline Q wave data outside the distribution of acute injury should broaden the prognostic insights from STEMI patients with a prior MI.