Abstract score. Basal and 3 months follow

AbstractBackground:Followingacute ST elevation myocardial infarction (STEMI), restoration of large-vesselpatency does not mean complete perfusion recovery, and perfusion of themicrovasculature is an additional prerequisite for obtaining optimal recovery (1).QRS score appears to be important in the early risk stratification for STEMI (2).

QRS score derived from simpleand widely available electrocardiogram (ECG) may be a useful parameter forassuring the presence of microvascular obstruction (3).Aim of the work: The aim of thisclinical study is to validate the 90 minutes modified Selvester  QRS score reduction as a reliable predictor ofmyocardial salvage, represented by 3 months global longitudinal strain (GLS)value, following successful reperfusion of acute STEMI.Material/Methods:The studypopulation included 400 patients presented with first acute STEMI withsuccessful reperfusion by thrombolysis (Group I- 200 patients: mean age=57.

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1 ± 11.6years) or primary percutaneous intervention (PPCI) (Group II- 200 patients: meanage=58.2±9.8 years). Basal and 90 minutes after reperfusion electrocardiographywas done with assessment of ST resolution and modified Selvester QRS score. Basaland 3 months follow up echocardiography was performed with assessment ofejection fraction (EF) and GLS as an indicator for myocardial salvage with itsimpact on long-term clinical outcome.

   Results:  90 minutes ST resolution and QRS scorereduction were significantly higher in PPCI group (P.: 0.04*, 0.03*). Patientsin group I had non-significant improvement of EF (P.: 0.22) during follow-up,but highly significant improvement of GLS (P.: ?0.

001**) compared to the basalechocardiographic study. Patients in group II had significant improvement of EF(P.: 0.01*) during follow-up, and highly significant improvement of GLS (P.

:?0.001**) compared to the basal echocardiographic study. As regardingcorrelation with 3 months GLS value, there was highly significant negativecorrelation between 3months GLS and (ST resolution and QRS score reduction)(P.: ?0.001**). Receiver operating characteristics (ROC) curve analysis showsthat 90 minutes QRS score reduction has the best cut off value of 70% topredict 3months GLS improvement with 80% sensitivity and 79% specificity.Conclusions:Modified SelvesterQRS score reduction 90 minutes after reperfusion is a cheap bedside ECGparameter added to ST resolution, can be considered as a reliable predictor offuture myocardial salvage with its impact on long-term clinical outcome andmodifying management strategies.

Keywords:  Modified Selvester QRS score • Myocardialinfarction• Myocardial salvage Corresponding author: Islam Ghanem AhmedGhanem,01100224180, 01001270412. [email protected]

com·        Introduction: -Followingrevascularization of acute STEMI patients, despite the restoration oflarge-vessel flow, tissue perfusion in the area at risk frequently continues tobe compromised. Persistent microcirculatory impairment is associated with poorrecovery of contractile function and adverse clinical outcomes. Thus,restoration of large-vessel patency does not mean complete perfusion recovery,and perfusion of the microvasculature is an additional prerequisite forobtaining optimal recovery (1). The modifiedSelvester QRS score (Table 1) based on ECG criteria capable of generating atotal of 29 points with each point in the score corresponding to 3% of the leftventricular (LV) mass (4).Global longitudinal strain (GLS)is considered an effective parameter for quantifying left-ventricular functionmore sensitive than LV ejection fraction (EF) assessed by two-dimensional (2D)echocardiography and their role in large MI has been previously reported (5),even in patients with a relatively preserved LV function after acute MI (6).Vartdal et al.

(2007) (7) showed that global peak negativestrain correlated well with final LV infarct size in patients with AMI.Global longitudinal strain (GLS) is calculated as theaverage of the observed segmental values of peak LS from the three apical views(8). GLS measures less than (-20%) is considered abnormal (9).The aim of thisclinical study is to validate the 90 minutes modified Selvester QRS score reductionas a reliable predictor of myocardial salvage, represented by 3 months GLSvalue, following successful reperfusion of acute STEMI.

·        Subjectsand methods: -§ Studydesign and population:     This clinical study included 400 patientswith first time acute STEMI who were admitted to the coronary care unit (CCU)and cathlab. units of cardiology department at Zagazig University, Egypt andKaohsiung Chang Gung Memorial Hospital, Taiwan during the period from November2015 to November 2017.§  Inclusioncriteria of the study:   We includedpatients who were admitted with first acute STEMI with successful reperfusion eitherby PPCI or thrombolytic therapy.§ Exclusioncriteria of the study: ·        Failed reperfusion orrevascularization.

·        History of myocardialinfarction.·        History of previous PCI or coronaryartery bypass graft (CABG).·         History of heart muscle diseases(cardiomyopathies).·        History of significant valvulardiseases.·        Significant arrhythmias(including atrial fibrillation and frequent extra-systoles).·        Previous pacemaker orcardioverter-defibrillator implantation.

·        Very poor image quality. § Ethical consideration:Consent was obtained from every patient after explanation of theprocedure. Medical research and ethics committee approved the study.§ Patientgroups:Wecategorized patients into 2 groups:Group I (200 patients): Patients withfirst acute STEMI with successful reperfusion by thrombolytic therapy.

Group II (200 patients): Patients withfirst acute STEMI with successful reperfusion by PPCI.Successfulreperfusion was documented by more than 70% resolution of ST segment elevation90 minutes after revascularization (10) § Data collection:Data werecollected for all patients including:§  Completehistory taking: Including name, age, gender, special habits, menstrualstate, drug history and previous hospital admission with special considerationto history of risk factors to ischemic heart disease (Hypertension: HTN, diabetesmellitus: DM, smoking, dyslipidemia) and co-morbid conditions.§  Thoroughclinical examination: All patients were subjected to thorough clinical general andlocal cardiac examination with special emphasis on hypotension and elevatedjugular venous pulse in the presence of clear lung fields.·        Electrocardiography (ECG):ECG machine(BTL-08 SD1, BTL Industries Inc., USA and MAC 5500 GE HealthcareMUSE v8, USA) was used to record standard 12-lead ECGs.

They were recorded at apaper speed of 25 mm/ second (s) and a gain of 10 mm/mv.   Twelve-lead ECG was performed directlybefore and 90 min after reperfusion. We analyzed the sum of elevations of STsegments in all leads and the modified Selvester QRSscore (Table 1) based on ECG criteria capable of generating a total of 29points with each point in the score corresponding to 3% of the left ventricular(LV) mass. ·        Echocardiography:           Restingtransthoracic echocardiography was performed for all patients using the Vivid 9system (GE Vingmed Ultrasound AS, Horten, Norway). Images were taken while thepatient is supine or in left lateral position Three apical scans of the leftventricle in the three-chamber, four-chamber, and two-chamber views with ECGtriggering according to the guidelines of the American Society ofEchocardiography were performed (12).Two examinations were done, the first is immediately after reperfusion and thesecond is 3 months later. The followingmeasurements were taken:(A)  Ejection fraction (EF): The LV volumesand ejection fraction (EF) were determined using the modified Simpson biplanetechnique from the apical 4- and 2-chamber views.

           It is calculated also from theformula:            EF= (EDV- ESV)? EDV ×100           Normally it is50 – 70 % (13). (B)  Strainechocardiography (STE) using the speckle tracking technique:                       STE is an echocardiographic, non-Dopplermethod that analyzes the longitudinal strain (LS) of LV segments by assessingthe deformation of an object relative to its original length. STE is performedin typical apical views with frame rate of 60 to 90 frames/sec, and strain willbe automatically measured. The technique of strain measurement requiresmanually outlining the LV endocardial contourthen the software analyzed the speckles within the myocardium and calculatesthe segmental strain, and afterward, the system automatically generatesmyocardial contour in the late systolic phase. Patients in whom more than foursegments can’t be analyzed will be excluded.

The system generates curves of LSfor each segment of the left ventricle, from which we estimate peaklongitudinal strain (LS) during the cardiac cycle. Peak systolic strain wasdefined as the peak negative strain value during systole (14). Global LS (GLS) iscalculated as the average of the observed segmental values of peak LS from thethree apical views (8).GLS measures less than (-20%) is considered abnormal (9).·        Reperfusion of acute STEMI:Reperfusion ofacute STEMI was done in all patients using thrombolytic therapy or primary PCI.Primary PCI was done using femoral or radial access. Imaging the non-infarctrelated artery (non-IRA) was done first. Then, IRA angiogram was done, thrombusaspiration and glycoprotein IIb-IIIa inhibitors infusion was done in highthrombus burden lesions.

TIMI III flow, grade III myocardial blush andcorrected TIMI frame count (CTFC) less than 27 were achieved in all patients.Statistical analysis Datawere then imported into Statistical Package for the Social Sciences (SPSSversion 20.0) software for analysis. Quantitative data were expressed as means±SD and qualitative data were expressed as absolute frequencies (number) & relative frequencies (percentage). Differences betweenmeans in two parametric groups were compared by Student’s t test.Non-parametric data by Chi-square test.

Bivariate correlation was used to studyassociation between two continuous variables. Multivariate Logistic regressionanalysis was used to detect independent predictor of certain parameter. P valuewas set at <0.05 for significant results & <0.

001 for highsignificant results (15).Results Inour study, we enrolled 400 patients with first time acute STEMI who wereadmitted to the coronary care unit (CCU) and cathlab. units of cardiologydepartment at Zagazig University, Egypt and Kaohsiung Chang Gung MemorialHospital, Taiwan during the period from November 2015 to November 2017.

 As regarding demographicdata and risk Factors, there was non-significant difference betweenpatients of both groups regarding age (P.: 0.42) and gender (P.

: 0.27). Also,there was non-significant difference between both groups regarding the riskfactors of coronary artery disease like hypertension (P.

: 0.51), diabetesmellitus (P.: 0.33) and smoking (P.: 0.38). But there was significantstatistical difference between both groups regarding dyslipidemia (P.

: 0.01).As regarding ECGdata, 90 minutes ST resolution and QRS score reduction were significantlyhigher in PPCI group (P.: 0.04*, 0.03*).

As regarding echocardiographicdata, patients in group I had non-significant improvement of EF (P.: 0.22)during follow-up, but highly significant improvement of GLS (P.: ?0.001**)compared to the basal echocardiographic study.Patients ingroup II had significant improvement of EF (P.: 0.01*) during follow-up, andhighly significant improvement of GLS (P.

: ?0.001**) compared to the basalechocardiographic study.As regardingcorrelation with 3 months GLS value, there was highly significant negativecorrelation between 3mo. GLS and ST resolution (Figure 1) and QRS scorereduction (Figure 2) (P.: ?0.001**).ROC curveanalysis shows that 90 minutes QRS score reduction has the best cut off valueof 70% to predict 3months GLS improvement with 80% sensitivity and 79%specificity (Figure 3).

 DiscussionQRS scoreappears to be important in the early risk stratification for STEMI (2). Thepresence of high QRS score is an independent predictor of incomplete STrecovery and 30-day MACE in STEMI treated with primary PCI (16).Assessmentof infarct size by echocardiography after PCI in patients with STEMI wassuperior with GLS when compared with LVEF. Since global strain is aninexpensive test, these data may be of health economic interest (17).Our studyshowed that there was non-significant difference between patients of bothgroups regarding age (P.: 0.42) and gender (P.: 0.

27). Also, there wasnon-significant difference between both groups regarding the risk factors ofcoronary artery disease like hypertension (P.: 0.51), diabetes mellitus (P.:0.33) and smoking (P.: 0.38), but significant regarding dyslipidemia (higher inthrombolysis group) (P.

: 0.01).Thus, oursample population is to an extent matched. we can notice that among our samplesize, Taiwanese population had less incidence of dyslipidemia compared toEgyptian population. We attribute that to less caloric diet, more exerciseprogram adoption and heathier lifestyle. Our studyshowed that 90 minutes ST resolution was significantly higher in PPCI group(P.: 0.

04*) and this is in agreement with Rahman et al., 2016 which reportedthat ST-segment resolutions were significantly more in PPCI than thrombolysisat 90 minutes (73.15±18.76 vs 60.06±23.

33%, p<0.015) (18).Our studyshowed that 90 minutes QRS score reduction was significantly higher in PPCI(P.: 0.

03*).Abdel-Salam et al., 2010 reported that the mean QRSscore was significantly lower in the ST resolution group compared to thenon-resolution group (2.88 +/- 1.

34 vs 5.93 +/- 1.56, respectively, p <0.001) (19).Our results showedthat, there was non-significant difference between echocardiographic parametersof the studied groups during the acute STEMI (P.

: 0.08 forbasal EF and 0.2 for basal GLS, however all parameters in both groups denoteimpaired systolic and diastolic LV function during acute STEMI (Stunning).Earlyassessment of LV-EF after acute MI can be misleading (20) because it isaffected by the presence of myocardial stunning, thus it may not distinguishviable from nonviable myocardium (21).But thefollow-up parameters showed more significant improvement of LV function in PPCIgroup (P.

: 0.02* for 3mo. EF, ?0.001** for 3mo. GLS).

Similar results werereported by Ottervanger et al.,2001 (22).Left ventricular GLSas measured by 2D speckletracking echocardiography immediately after primary PCI hasalso been shown to be an excellent predictor of adverse LV remodeling andcardiac events in patients with acute myocardial infarction. As comparedto LVEF, GLS has the advantage of minimal inter-observer variability (23).Liszka et al.

, 2014 suggested that impaired indices of LVdeformation detected 3 days and 30 days after AMI may provide importantpredictive value in LV remodeling and patients’ follow-up (24).Our resultsshowed highly significant negative correlation between 3months GLS and (STresolution and QRS score reduction) (P.: ?0.001**). Theabsence of ST-segment elevation resolution after PCI was also associated with alack of left ventricular function recovery. Numerous studies from thefibrinolytic era have found that the absence of ST-segment elevation resolutionafter reperfusion has been associated with poor outcomes, including largerinfarct size and increased mortality (25).

This is inagreement with Watanabe et al., 2015 who indicated that the QRS scorederived from simple and widely available ECG may be a useful parameter forassuring the presence of microvascular obstruction (3).ROC curveanalysis shows that 90 minutes QRS score reduction has the best cut off valueof 70% to predict 3months GLS improvement with 80% sensitivity and 79%specificity (Figure 3). It may beargued that the primary outcome is a surrogate marker rather than a hard clinical endpoint.However, in a carefully selected cohort of low-intermediate risk STEMI patientsin which hard outcome variables such as in-hospital mortality and morbidity werenegligibly low, LV systolic function recoveryrepresented by 3 months GLS improvement exemplifies a valid surrogate endpointto detect the differences in outcomes of the treatment strategies adopted. ConclusionsGLS measurement (compared to EF) early after STEMI is areliable predictor for myocardial functional recovery assessed 3 months later,which surely would be expressed on the clinical outcomes. PPCI leads to bettermyocardial salvage compared with fibrinolysis.

Modified Selvester QRS scorereduction 90 minutes after reperfusion is a cheap bedside ECG parameter addedto ST resolution, can be considered as a reliable predictor of future myocardialsalvage with its impact on long-term clinical outcome and modifying managementstrategies.Limitations Due to lowevent rate in selected low-intermediate risk STEMI patient, we couldn’t rely onmajor adverse cardiac event (MACE) as a hard clinical endpoint to validate theQRS score for prediction of long-term outcomes.Conflict of interest None.  

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