Assessment of the Right Ventricular Function and Extent of Ischemic Injury in Patients treated with Primary Percutaneous Coronary Intervention
primary percutaneous coronary intervention ; right ventricular infarction ; myocardial infarction ; cardiac magnetic resonance imaging
Objectives:This study_was_designed_to1) determine the impact of initial clinical and angiographic status and salutary effect of PPCI on the presence and size of RVI confirmed by CMRI LE.2) determine the clinical and angiographic factors influencing the presence of ST segment elevation ≥ 1mm V4R and to verify whether the presence of ischemia in the right precordial ECG leads resulting in the presence of irreversible necrosis in the RV wall.MethodsClinical, cardiac magnetic resonance and angiographic data of 114 prospectively collected patients (males 79, females 35, mean age 60 ± 10 years) with acute inferior MI were analyzed. All Subjects underwent emergency angiography and PPCI, followed by CMRI 3-5 days after the infarction for assessing the presence of late enhancement in the RV wall. On admission 16-lead electrocardiogram, was recorded. Right Ventricular Ischemia was defined as ST-segment elevation of more than 0.1 mV in lead V4R.ResultsLate Enhancement Cardiovascular Magnetic Resonance Imaging detected RVI in 48 of 114 (42%) patients with acute inferior MI.In 66 ; patients, there was no presence of RVI (RVI-). After coronary angiography, single vessel coronary artery disease was found in 69 (61%) cases, double vessel disease in 30 (26%) and three-vessel disease in 15 (13%). In both groups RVI(-) &RVI(+). the percentage distributions of multivessel disease and distributions ; of RCA obstruction were similar. The flow in the main RCA before the procedure, evaluated in the TIMI scale and degree of development of the collateral circulation assessed by Rentrop scale, did not differ significantly in the analyzed groups. Multivariable model was constructed to identify preprocedurals predictors of the presence of LE in RV wall, such as TIMI in main RCA vessel, site of RCA occlusion, Rentrop score, Preinfarction Angina (PA), time of ischemia, Gensini score, Leaman score, Hgb level, RV hypertrophy, flow disturbances in RVB;s. In a multivariable logistic regression analysis for preprocedural factors number of lost RVB’s concomitant with the lack of PA in a period <24 h before MI, were the only preprocedural predictors of the RVI occurrence. (OR = 2,63 , 95% CI: 1.67 to 4,15; p<0,001); (OR = 0,33, 95% CI: 0,13 to 0,89, p<0,03 respectively). Logistic regression model was constructed for periprocedural and postprocedural variables was constructed Taking into account parameters such as the administration of Abciximab, the use of thrombectomy, the number of implanted stents, the total length of implanted stents, maximal pressure, posprocedural angiographic parameters such as flow disturbances in the main RCA vessel, the RVBI value, abnormal flow in the RVB/ RVB’s, the presence of distal embolization of RPD, the number of lost left ventricular branches. Flow in th ; e main RCA after procedure did not differ between these two groups. Complete reperfusion, defined as normal flow in the right main coronary artery and its major right ventricular branches, was achieved in 56 (50%) patients. The incidence of TIMI<2 flow in at least one RVB was present in 37 (77%) patients in RVI(+) group, while only in 1 (0,8%) case in RVI(-) group (p<0,001). Embolization of distal RPD after procedure occurred in 24 (21%) of all patients, in 21 (44%) cases in RVI(+), and 3 (5%) in RVI(-) group, (p <0.001). Statistical model for periprocedural and postprocedural factors affecting the presence of RVI, built on the basis of hierarchical logistic ; regression multivariable analysis, proved to be the best model for factors acting before during and after the procedure. Simultaneous co-existence of TIMI flow grade<2 in at least one RVB, and distal RPD embolization predicted the presence of RVI with the good sensitivity and specifity (AUC 95 CI 0,97 (0,94-1) (OR=290, 95% CI:28 to 2994, p<0,001;OR =1553, 95% CI:3 to 25771, p<0,001) respectively. Group of 48 patients with RVI was divided into two groups; one with small RVI and the second with large RVI, based on the median of RVIS (Right Ventricular Infarct Size defined as RV_LE mass/RVmass *100%), In univariate logistic regression analysis taking into account preprocedural, periprocedu and postprocedural factors affectin ; g presence of RVI, the only two postprocedural factors which determined RVIS, were distal RPD embolization (OR=3,34 (95% CI 1,01-11,1,p=0,049) and RVBI (OR= 41,84 (95% CI 2,13-823,3; p=0,001). Multivariable logistic regression analysis revealed RVBI as the only independent predictor of infarct size (OR = 24,2 (95% CI 1,12-523,9; p=0,004). The median value for RVEF in group with large RVI was 43% (min. 27%-max.65%). The median value for RVEF in group with small RVI was=54% (41% -73%),(p <0.001) Values of median for the groups with small RVI, and RVI (-) did not differ from each other statistically_significant (p = 0.43). As_a result_of the hierarchical multivariate logistic regression taking into account_above mentioned preprocedural variables, a model that best predicted the presence of elevation ST ≥ 1 mm in V4R was TIMI<3 flow in at least_one RVB, if there_were no PA in the period of 24 h before MI (OR = 6,51, 95% CI: 2,37 to 17,93, p<0,001; OR = 0,38, 95% CI: 0,15 to 0,98, p<0,04 respectively). Reversible RV ischemia, visible_as the_presence of elevation ST ≥1 mm in V4 R was present in 83 (73%) cases which was in mild agreement with the CMRI LE- findings for RVI which revealed RVI necrosis in 48 (42%) patients.Conclusions:1. The optimal_outcome of PPCI, with_successful reperfusion both the main RCA, as well as all RVB’s with a diameter of ≥ 1 mm, effectively protects against ; RV wall necrosis, regardless of baseline clinical and angiographic conditions. ; 2. Right Ventricular Infarction size depended directly on the perfusion of RVFW, which in the most objective way expressed RVBI.3. The presence of ↑ST ≥ 1 mm in V4 R in the ECG at admission was caused by the presence of TIMI flow <3 in at least one RVB before the procedure with concomitant lack of preinfarction angina <24h.4. Ischemic changes in right_ventricular ECG at admission, proved to be merely a marker of reversible ischemia of the right ventricular free wall, which did not result in the presence of irreversible damage to the right ventricle in case of optimal PPCI outcome.