Diagnostic and Prognostic Value of Lead aVR During Exercise Testing in Patients Suspected of Having Myocardial Ischemia

aVR ST-segment changes and prognosis of ST-segment elevation myocardial infarction

BACKGROUND

Clinical importance of aVR lead-related changes in predicting the prognosis of acute myocardial infarction remains uncertain. The present study aimed to assess the value of ST-segment changes in aVR lead and the outcome and sequels of the first episode of acute ST-segment elevation myocardial infarction.

METHODS

This prospective cohort study was conducted on patients suffering first episode of ST-segment elevation myocardial infarction and underwent percutaneous coronary intervention. Information was collected through hospital-recorded files reading. The electrocardiogram (ECG) was taken from the patients upon entering the hospital and followed-up for 30 days to assess cardiovascular complications.

RESULTS

In patients with anterior STEMI, with the use of multivariate analysis, admission aVR ST elevation ≥1 mm was found to be a strong and independent predictor of major cardiovascular adverse events (MACE) within 30 days of discharging (P value for trend .002). In patients with inferior (± RV) ST-segment elevation myocardial infarction (STEMI), with the use of multivariate analysis, admission aVR ST depression ≥1 mm was found to be a strong and independent predictor of MACE within 30 days of discharging (P value for trend .01).

CONCLUSION

In patients with anterior STEMI, admission aVR STE ≥1 mm was found to be a strong and independent predictor of MACE within 30 days of discharging. On the other hand, in patients with inferior STEMI, aVR ST depression ≥1 mm was found to be a strong and independent predictor of MACE within 30 days of discharging.

Lead aVR predicts early revascularization but not long-term events in patients referred for stress electrocardiography

BACKGROUND

Exercise stress electrocardiography (ExECG) is recommended as a first-line tool to assess ischemia, but standard ST-analysis has limited diagnostic accuracy. ST elevation in lead aVR has been associated with left main and LAD disease in the population undergoing coronary angiography but has not been studied in the general population undergoing stress testing for the initial evaluation of CAD without coronary angiography. We sought to determine the predictive value of lead aVR elevation for ischemia, early revascularization, and subsequent cardiac events in consecutive patients undergoing ExECG.

METHODS AND RESULTS

The study cohort included 641 subjects referred for ExECG who were dichotomized by presence or absence of aVR elevation ≥1mm and compared for prevalence and predictors of ischemia and a composite of cardiac death, nonfatal myocardial infarction, and late revascularization. The cohort had a median age of 57 and 57% were male. The prevalence of aVR elevation was 11.5%. The prevalence of significant ischemia on patients who received imaging was significantly higher with aVR elevation (14.3% vs 2.3%, p<0.001). Early revascularization occurred in 10.9% with vs 0.2% without aVR elevation, p<0.001. No subjects without aVR elevation or ST-depression underwent early revascularization. However, cardiac event rates were similar over a median 4.0 years of follow-up with and without aVR elevation (2.8% vs. 2.6%, p = 0.80). aVR elevation did not predict long-term cardiac events by Kaplan-Meier survival analysis (p = 0.94) or Cox proportional hazards modeling (p = 0.35).

CONCLUSIONS

aVR elevation during ExECG predicts ischemia on imaging and early revascularization but not long-term outcomes and could serve as a useful adjunct to standard ST-analysis and potentially reduce the need for concurrent imaging.

Incremental value of high-frequency QRS analysis for diagnosis and prognosis in suspected exercise-induced myocardial ischaemia

Aim:

Exercise stress testing is used to detect myocardial ischaemia, but is limited by low sensitivity and specificity. The authors investigated the value of the analysis of high-frequency QRS components as a marker of abnormal depolarization in addition to standard ST-deviations as a marker of abnormal repolarization to improve the diagnostic accuracy.

Methods and results:

Consecutive patients undergoing bicycle exercise stress nuclear myocardial perfusion imaging were prospectively enrolled. Presence of myocardial ischaemia, the primary diagnostic endpoint, was adjudicated using MPI and coronary angiography. Automated high-frequency QRS analysis was performed in a blinded fashion. The prognostic endpoint was major adverse cardiac events (MACEs) during two years of follow-up. Exercise-induced ischaemia was detected in 147/662 patients (22%). The sensitivity of high-frequency QRS was similar to ST-deviations (46% vs. 43%, p=0.59), while the specificity was lower (75% vs. 87%, p&lt;0.001). The combined use of high-frequency QRS and ST-deviations classified 59% of patients as ‘rule-out’ (both negative), 9% as ‘rule-in’ (both positive) and 32% in an intermediate zone (one test positive). The sensitivity for ‘rule-out’ and the specificity for ‘rule-in’ improved to 63% and 97% compared with ST-deviation analysis alone (both p&lt;0.001). MACE-free survival was 90%, 80% and 42% in patients in the ‘rule-out’, intermediate and ‘rule-in’ groups (p&lt;0.001). After adjustment for age, gender, ST-deviations and clinical post-test probability of ischaemia, high-frequency QRS remained an independent predictor for the occurrence of MACEs.

Conclusion:

The use of high-frequency QRS analysis in addition to ST-deviation analysis improves the diagnostic accuracy during exercise stress testing and adds independent prognostic information.

Prognostic implications of ST-segment elevation in lead aVR in patients with acute coronary syndrome: A meta-analysis

BACKGROUND

ST-segment elevation (STE) in lead aVR is a useful tool in recognizing patients with left main or left anterior descending coronary obstruction during acute coronary syndrome (ACS). The prognostic implication of STE in lead aVR on outcomes has not been established.

METHODS

We performed a systematic search for clinical studies about STE in lead aVR in four databases including PubMed, EMBASE, Cochrane Library, and Web of Science. Primary outcome was in-hospital mortality. Secondary outcomes included in-hospital (re)infarction, in-hospital heart failure, and 90-day mortality.

RESULTS

We included 7 studies with a total of 7,700 patients. The all-cause in-hospital mortality of patients with STE in lead aVR during ACS was significantly higher than that of patients without STE (OR: 4.37, 95% CI 1.63 to 11.68, p = .003). Patients with greater STE (>0.1 mV) in lead aVR had a higher in-hospital mortality when compared to lower STE (0.05-0.1 mV) (OR: 2.00, 95% CI 1.11-3.60, p = .02), However, STE in aVR was not independently associated with in-hospital mortality in ACS patients (OR: 2.72, 95% CI 0.85-8.63, p = .09). The incidence of in-hospital myocardial (re)infarction (OR: 2.77, 95% CI 1.30-5.94, p = .009), in-hospital heart failure (OR: 2.62, 95% CI 1.06-6.50, p = .04), and 90-day mortality (OR: 10.19, 95% CI 5.27-19.71, p < .00001) was also noted to be higher in patients STE in lead aVR.

CONCLUSIONS

This contemporary meta-analysis shows STE in lead aVR is a poor prognostic marker in patients with ACS with higher in-hospital mortality, reinfarction, heart failure and 90-day mortality. Greater magnitude of STE portends worse prognosis. Further studies are needed to establish an independent predictive role of STE in aVR for these adverse outcomes.

Is isolated ST segment elevation in Lead aVR associated with high grade coronary artery disease?

BACKGROUND

The diagnostic accuracy of lead aVR ST-segment elevation for left main or triple vessel disease (LM/3VD) has not been universally accepted. In the present analysis we sought to evaluate the diagnostic accuracy of STEaVR in patients presenting with an acute coronary syndrome (ACS).

METHODS

Pooled sensitivity, specificity, positive, and negative likelihood ratios were calculated using a random effects model (DerSimonian-Laird Method) for computing summary estimates and receiver operator curve (ROC) analysis for evaluating overall diagnostic accuracy.

RESULTS

This meta-analysis included 14 studies. The pooled sensitivity of STEaVR for LM/3VD was 0.40 (95% CI; 0.38 0.43, p < 0.001), specificity 0.82 (95% CI; 0.81-0.83, p < 0.001). Pooled positive likelihood ratio 2.49 (95% CI; 1.62-3.81, p < 0.001) and negative likelihood 0.54 (95% CI; 0.39-0.76, p < 0.001). The pooled sensitivity of STEaVR for LM was 0.39 (95% CI; 0.34-0.45, p < 0.001) specificity was 0.86 (95% CI; 0.85-0.87, p < 0.001) with an AUC of 0.79. The pooled positive likelihood ratio (LR) for LM was 2.78 (95% CI, 2.28-3.39, p < 0.001) negative likelihood ratio 0.51 (95% CI, 0.33-0.78, p < 0.001).

CONCLUSION

Our study shows that in patients presenting with an ACS, presence of STEaVR may indicate the presence of LM or 3VD. STEaVR has a high specificity for both LM and 3VD, with a high pooled LR.

Electrocardiographic changes in patients with acute myocardial infarction caused by left main trunk occlusion

BACKGROUND

Left main trunk (LMT) occlusion is a rare angiographic finding. The primary purpose was to investigate the ECG pattern of patients with angiographic confirmation of LMT as culprit lesion.

METHODS

Forty-eight patients (32 men; mean age 73 years) with angiographic total (21 patients; 44%) or subtotal (27 patients; 56%) occlusion of the LMT were analyzed. Twenty patients (42%) were found to have concomitant coronary lesions. Eighteen patients (38%) required intra-aortic balloon pump support.

RESULTS

A significant left axis deviation was observed in 26 cases (54%) and an intraventricular conduction delay in 32 patients (67%). The average QRS width and QTc interval were 122 and 433 ms, respectively. ST-segment elevation in lead aVR occurred in 32 patients (67%). ST-segment elevation in leads V2-5 and in leads I and aVL [classic left anterior descending (LAD) type] was frequently observed (18 cases; 35%). In six patients (13%), a partial LAD type was observed with ST-segment elevation in leads I and aVL, but not in peripheral leads. The remaining patients showed ST-segment elevation only in peripheral leads (12 cases), in inferior leads III + aVF (six cases), whereas six patients had no ST-segment elevation. Diffuse ST-segment depression only (>6 leads) was observed in 15 cases (31%). Eighteen patients (38%) died during hospitalization.

CONCLUSION

ST-segment elevation in lead aVR or a LAD-type pattern can be associated with LMT disease. Other relevant aspects are the presence of cardiogenic shock at admission, the left axis deviation and marked prolongation of QTc interval and QRS width.

Automatically computed ECG algorithm for the quantification of myocardial scar and the prediction of mortality

BACKGROUND

Myocardial scar is associated with adverse cardiac outcomes. The Selvester QRS-score was developed to estimate myocardial scar from the 12-lead ECG, but its manual calculation is difficult. An automatically computed QRS-score would allow identification of patients with myocardial scar and an increased risk of mortality.

OBJECTIVES

To assess the diagnostic and prognostic value of the automatically computed QRS-score.

METHODS

The diagnostic value of the QRS-score computed automatically from a standard digital 12-lead was prospectively assessed in 2742 patients with suspected myocardial ischemia referred for myocardial perfusion imaging (MPI). The prognostic value of the QRS-score was then prospectively tested in 1151 consecutive patients presenting to the emergency department (ED) with suspected acute heart failure (AHF).

RESULTS

Overall, the QRS-score was significantly higher in patients with more extensive myocardial scar: the median QRS-score was 3 (IQR 2-5), 4 (IQR 2-6), and 7 (IQR 4-10) for patients with 0, 5-20 and > 20% myocardial scar as quantified by MPI (p < 0.001 for all pairwise comparisons). A QRS-score ≥ 9 (n = 284, 10%) predicted a large scar defined as > 20% of the LV with a specificity of 91% (95% CI 90-92%). Regarding clinical outcomes in patients presenting to the ED with symptoms suggestive of AHF, mortality after 1 year was 28% in patients with a QRS-score ≥ 3 as opposed to 20% in patients with a QRS-score < 3 (p = 0.001).

CONCLUSIONS

The QRS-score can be computed automatically from the 12-lead ECG for simple, non-invasive and inexpensive detection and quantification of myocardial scar and for the prediction of mortality. TRIAL-REGISTRATION: http://www.clinicaltrials.gov . Identifier, NCT01838148 and NCT01831115.