Q Waves at Presentation in Patients With ST-Segment–Elevation Myocardial Infarction

HomeCirculation: Cardiovascular InterventionsVol. 10, No. 11Q Waves at Presentation in Patients With ST-Segment–Elevation Myocardial Infarction Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBQ Waves at Presentation in Patients With ST-Segment–Elevation Myocardial InfarctionAn Underappreciated Marker of Risk Ajar Kochar, MD and Christopher B. Granger, MD Ajar KocharAjar Kochar From the Duke Clinical Research Institute, Duke University Medical Center, Durham, NC. and Christopher B. GrangerChristopher B. Granger From the Duke Clinical Research Institute, Duke University Medical Center, Durham, NC. Originally published16 Nov 2017https://doi.org/10.1161/CIRCINTERVENTIONS.117.006085Circulation: Cardiovascular Interventions. 2017;10:e006085The degree of myocardial salvageability and the management of patients with ST-segment–elevation myocardial infarction (STEMI) is time sensitive; thus, clinicians must use readily available data to glean prognostic information and to guide clinical decisions. ECGs, the backbone of STEMI diagnosis, are rapidly obtained and contain a wealth of prognostic data. Data from clinical trial databases of patients with STEMI have shown that the presence of Q waves is associated with adverse cardiovascular outcomes, including higher mortality.1–3 Moreover, the prognostic significance of Q waves has been shown to exceed that of time since symptom onset, the variable most often used to assess the suitability of reperfusion therapy related to the time course of infarction.2 However, this relationship between Q waves on baseline ECG for STEMI patients and adverse cardiovascular outcomes has not been described in unselected patient populations treated in routine clinical practice.See Article by Zheng et alIn this issue of Circulation: Cardiovascular Interventions, Zheng et al4 sought to quantify this relationship in a registry of consecutive STEMI patients admitted to 5 hospitals in Edmonton, Canada. There were 3593 STEMI patients admitted from 2006 to 2011; after exclusions, the analysis cohort consisted of 2290 patients. These patients underwent primary percutaneous coronary intervention (PCI), pharmacoinvasive strategy, or no acute reperfusion. The rate of Q waves at baseline was higher for men with longer time from symptom to baseline ECG (P-trend<0.001); however, the association of Q waves with longer times was not statistically significant for women (P-trend=0.152), adding credence to similar previous observations.5 The adjusted relationship between presence of Q waves on baseline ECG and a composite outcome consisting of congestive heart failure, cardiogenic shock, reinfarction, and death showed substantially higher risk with Q waves (odds ratio, 1.65; 95% confidence interval, 1.18–2.30). Alternatively, there was not a statistically significant association between total ischemic time, defined as time from symptom onset to treatment time, and the composite clinical outcome in this data set. Furthermore, there was no significant interaction between the STEMI management strategy—P-PCI, pharmacoinvasive, or no acute reperfusion—and the presence of Q waves with respect to the association with occurrence of the composite clinical outcome.These data build on previous work in patients with STEMI that established the prognostic value of Q waves. During the fibrinolytic therapy era, data from clinical trials revealed that Q waves were associated with a lower in-hospital ejection fraction and higher 30-day mortality.1,6 This relationship between Q waves and poor cardiovascular outcomes was also appreciated in patients undergoing primary PCI. Data from the APEX-AMI trial (Assessment of Pexelizumab in Acute Myocardial Infarction) demonstrated that the presence of Q waves was associated with higher rates of 90-day mortality (and with less successful reperfusion as measured by angiography and by ST-segment resolution).2 This association between the presence of Q waves and adverse outcomes in a STEMI cohort treated with PCI was further strengthened by an analysis of the PLATO trial (Platelet Inhibition and Patient Outcome). In the PLATO trial, 46% of STEMI patients had baseline Q waves, and there was a significant association between Q-wave and all-cause mortality. Notably, in this PLATO analysis, time to treatment was not significantly associated with mortality.3Findings from the study by Zheng et al, in combination with previous studies, confirm that Q waves are more strongly associated with adverse cardiovascular outcomes than is time from symptom onset. Why is this? Time from symptom onset is a pivotal determinant of the extent of the ischemic wavefront; the longer the ischemic time, the greater the degree of myocardial necrosis. However, the estimation of symptom onset may be imprecise, and symptoms may be stuttering. Furthermore, symptom onset to treatment does not fully reflect the ischemic time nor the consequences, as the obstruction may be dynamic, the obstructed artery may spontaneously recanalize, and collaterals may modulate the time course of infarction.7,8 Alternatively, magnetic resonance imaging studies demonstrate that the presence of Q waves correlates with the total extent of infarcted tissue.9,10 Thus, Q waves may often be a more direct reflection of the magnitude of myocardial necrosis in comparison with time since symptom onset. Another important observation in this analysis was that the absence of Q waves was associated with a greater extent of ST resolution, suggesting that lack of Q waves may be a marker for degree of salvageability. It is important to note, however, that even in the presence of Q waves, most patients has successful reperfusion, as measured by ST-segment resolution after therapy.For patients presenting >12 hours after symptom onset, the 2013 American College of Cardiology/American Heart Association guidelines provide a Class IIa; Level of Evidence B, recommendation for reperfusion therapy for those who have clinical and ECG evidence of ongoing ischemia, with a preference for primary PCI as the reperfusion strategy.11 This study suggests that the absence of Q waves in this situation could be another factor to take into account to support the pursuit of a reperfusion strategy. A key implication from this (and previous related) studies is that the association of extent and completion of infarction and related opportunity for salvage, for which we typically use time from symptom onset to treatment to measure, is substantially enhanced by taking into account presence of Q waves.The study by Zheng et al extends a previous observation that Q waves present on baseline ECGs of STEMI patients correlates with mortality, in a cohort of unselected patients who were treated in routine clinical practice. These findings underscore the prognostic value derived from the simple, cheap, and readily available ECG, as well as the underappreciated significance of baseline Q waves to discriminate risk and potentially guide therapy.FootnotesThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.Correspondence to Christopher B. Granger, MD, Duke Clinical Research Institute, Duke University Medical Center, DUMC Box 3850, Durham, NC 27715. E-mail [email protected]References1. Andrews J, French JK, Manda SO, White HD. New Q waves on the presenting electrocardiogram independently predict increased cardiac mortality following a first ST-elevation myocardial infarction.Eur Heart J. 2000; 21:647–653. doi: 10.1053/euhj.1999.1908.CrossrefMedlineGoogle Scholar2. Armstrong PW, Fu Y, Westerhout CM, Hudson MP, Mahaffey KW, White HD, Todaro TG, Adams PX, Aylward PE, Granger CB. Baseline Q-wave surpasses time from symptom onset as a prognostic marker in ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention.J Am Coll Cardiol. 2009; 53:1503–1509. doi: 10.1016/j.jacc.2009.01.046.CrossrefMedlineGoogle Scholar3. Siha H, Das D, Fu Y, Zheng Y, Westerhout CM, Storey RF, James S, Wallentin L, Armstrong PW. Baseline Q waves as a prognostic modulator in patients with ST-segment elevation: insights from the PLATO trial.CMAJ. 2012; 184:1135–1142. doi: 10.1503/cmaj.111683.CrossrefMedlineGoogle Scholar4. Zheng Y, Bainey KR, Tyrrell BD, Brass N, Armstrong PW, Welsh RC. Relationships between baseline Q waves, time from symptom onset, and clinical outcomes in ST-segment–elevation myocardial infarction patients: insights from the Vital Heart Response Registry.Circ Cardiovasc Interv. 2017; 10:e005399. doi: 10.1161/CIRCINTERVENTIONS.117.005399.LinkGoogle Scholar5. Kaul P, Fu Y, Westerhout CM, Granger CB, Armstrong PW. Relative prognostic value of baseline Q wave and time from symptom onset among men and women with ST-elevation myocardial infarction undergoing percutaneous coronary intervention.Am J Cardiol. 2012; 110:1555–1560. doi: 10.1016/j.amjcard.2012.07.020.CrossrefMedlineGoogle Scholar6. Wong CK, Gao W, Raffel OC, French JK, Stewart RA, White HD; HERO-2 Investigators. Initial Q waves accompanying ST-segment elevation at presentation of acute myocardial infarction and 30-day mortality in patients given streptokinase therapy: an analysis from HERO-2.Lancet. 2006; 367:2061–2067. doi: 10.1016/S0140-6736(06)68929-0.CrossrefMedlineGoogle Scholar7. Fefer P, Hod H, Hammerman H, Boyko V, Behar S, Matetzky S; Acute Coronary Syndrome Israeli Survey (ACSIS) 2006 Study Group. Relation of clinically defined spontaneous reperfusion to outcome in ST-elevation myocardial infarction.Am J Cardiol. 2009; 103:149–153. doi: 10.1016/j.amjcard.2008.08.050.CrossrefMedlineGoogle Scholar8. Steg PG, Himbert D, Benamer H, Karrillon G, Boccara A, Aubry P, Juliard JM. Conservative management of patients with acute myocardial infarction and spontaneous acute patency of the infarct-related artery.Am Heart J. 1997; 134(2 pt 1):248–252.CrossrefMedlineGoogle Scholar9. Kaandorp TA, Bax JJ, Lamb HJ, Viergever EP, Boersma E, Poldermans D, van der Wall EE, de Roos A. Which parameters on magnetic resonance imaging determine Q waves on the electrocardiogram?Am J Cardiol. 2005; 95:925–929. doi: 10.1016/j.amjcard.2004.12.028.CrossrefMedlineGoogle Scholar10. Wu E, Judd RM, Vargas JD, Klocke FJ, Bonow RO, Kim RJ. Visualisation of presence, location, and transmural extent of healed Q-wave and non-Q-wave myocardial infarction.Lancet. 2001; 357:21–28. doi: 10.1016/S0140-6736(00)03567-4.CrossrefMedlineGoogle Scholar11. O'Gara PT, Kushner FG, Ascheim DD, Casey DE, Chung MK, de Lemos JA, Ettinger SM, Fang JC, Fesmire FM, Franklin BA, Granger CB, Krumholz HM, Linderbaum JA, Morrow DA, Newby LK, Ornato JP, Ou N, Radford MJ, Tamis-Holland JE, Tommaso CL, Tracy CM, Woo YJ, Zhao DX, Anderson JL, Jacobs AK, Halperin JL, Albert NM, Brindis RG, Creager MA, DeMets D, Guyton RA, Hochman JS, Kovacs RJ, Kushner FG, Ohman EM, Stevenson WG, Yancy CW; American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines.Circulation. 2013; 127:e362–e425. doi: 10.1161/CIR.0b013e3182742cf6.LinkGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Albiero R and Seresini G (2020) Subacute Left Ventricular Free Wall Rupture after Delayed STEMI Presentation During the COVID-19 Pandemic, JACC: Case Reports, 10.1016/j.jaccas.2020.06.040, 2:10, (1603-1609), Online publication date: 1-Aug-2020. Tiller C, Reindl M, Holzknecht M, Innerhofer L, Wagner M, Lechner I, Mayr A, Klug G, Bauer A, Metzler B and Reinstadler S (2019) Relationship between admission Q waves and microvascular injury in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention, International Journal of Cardiology, 10.1016/j.ijcard.2019.10.009, 297, (1-7), Online publication date: 1-Dec-2019. November 2017Vol 10, Issue 11 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/CIRCINTERVENTIONS.117.006085PMID: 29146675 Originally publishedNovember 16, 2017 KeywordsEditorialsheart failureregistryprognosisshock, cardiogenicmyocardial infarctionPDF download Advertisement SubjectsCatheter-Based Coronary and Valvular InterventionsQuality and OutcomesRevascularization