P237 INFLUENCE OF HEART RATE ON LEFT AND RIGHT VENTRICULAR LONGITUDINAL STRAIN IN PATIENTS WITH CHRONIC HEART FAILURE

Background

Myocardial deformation evaluated by two–dimensional speckle tracking echocardiography (STE) is a useful tool to evaluate both left and right ventricular function. However, there are no conclusive data about the relationship between strain measures and heart rate (HR).

Aim of the Study

To analyse changes in left (LV) and right ventricular (RV) longitudinal strain associated with variations of HR in patients with and without chronic heart failure (CHF). Methods. We enrolled 45 patients. Of the 38 patients diagnosed with CHF, 21 were carrying an ICD (Group 1), and 17 an ICD with CRT (Group 2). Group 3 included 7 participants without CHF with sinus node dysfunction that were carrying a pacemaker. The frequency of atrial stimulation was increased to 90 beats/min and an echocardiogram was performed at each increase of 10 beats/min. Global LV and RV longitudinal strain (LVGLS and RVGLS, respectively) and RV free wall longitudinal strain (RVfwLS) were calculated at each HR, together with other echocardiographic parameters. Worsening or improvement of strain measures was defined as a relative change from baseline of 10%.

Results

The reproducibility of strain measurements was assessed in all the images obtained at the different HRs for 19 of the study participants. A high degree of reproducibility was observed for LVGLS (ICC = 0.96; 95% CI, 0.93 – 0.97) as well as for RVGLS (ICC = 0.91; 95%CI, 0.86 – 0.94) and RVfwLS (ICC = 0.91; 95%CI, 0.85 – 0.94). When analysed as continuous variables, significant reductions in LVGLS were detected at higher HRs, whereas improvements in both RVGLS and RVfwLS were observed (left panels of the figure). Patients with worsening of LVGLS (76% overall) were more likely to present lower baseline LV function and maximum relative changes of LVGLS correlated significantly with the E/e’ ratios (r = –0.56; p < 0.001). Only few patients (18% for RVGLS and 16% for RVfwLS) exhibited HR–related worsening of RV strain measures, which was associated with lower levels of baseline RV function and higher pulmonary systolic pressures. Finally, 21 (47%) and 25 (56%) of the participants responded with improvements in RVGLS and RVfwLS, respectively. Right panels of the figure show the trend of left and right measures in the different groups.

Conclusions

Our findings revealed heterogeneous RV and LV responses to increases in HR. These findings might ultimately be used to optimize cardiac functionality at rest in patients diagnosed with CHF.

P243 RELEVANCE OF RENAL RESISTANCE INDEX INCREASE AFTER CORONARY ANGIOGRAPHY

Background

Renal resistance index is a Doppler derived measure which is able to reflect the pathophysiological background of Cardiorenal Syndrome (CS). There are no data about the influence of the intravascular administration of contrast media on RRI and its relationship with worsening of renal function (WRF).

Aim of the Study

To evaluate changes in renal resistance index (RRI) after coronary angiography in patients with and without WRF. METHODS We enrolled 115 patients (mean age 64 years, 73% males, 84% hypertensive, 43% diabetic, 30% with acute coronary syndrome, 21% affected by chronic heart failure, CHF, with a mean left ventricular ejection fraction, LVEF, of 51±11) with suspected coronary artery disease, stable angina, or acute coronary syndromes who have been referred for coronary angiography (with or without pre–existing renal impairment). Renal arterial echo–color Doppler was used to calculate RRI before and 48 hours after coronary angiography. WRF was defined as an increase of creatinine >0.3 mg/dl and of at least 25% from baseline 24–48 hours after coronary angiography.

Results

Fourteen (12%) among the enrolled patients showed WRF. As expected, a significant increase of creatinine serum levels was observed in patients with WRF (from 1.14±0.40 to 1.71±0.49, p < 0.001) but not those without (from 0.89±0.27 to 0.92±0.28, p n.s.) WRF. On the other hand, RRI significantly increased both in patients with (from 72.8±4.3 to 76.4±5.2, p < 0.05) and without (from 63.1±7.2 to 65.4±7.1, p < 0.05). However, both at baseline and after angiography, patients with WRF showed RRI values significantly greater when compared with those without. At ROC curve analyses for WRF, the baseline and after angiography RRI sowed similar AUC (0.88 and 0.90, respectively) and for both RRI values the best cut–off was 70% (sensitivity of 79% and 93% and Specificity of 93% and 82%, respectively). As shown in the figure, the high predictive accuracy of RRI values was due to the fact that, although increased after angiography, the proportion of patients without WRF and with RRI>70% remained very low.

Conclusion

After coronary angiography RRI significantly increase both in patients with and without WRF. However, a larger proportion of patients with WRF present a critically increased RRI, i.e. equal or above 70%, before and after angiography probably because reflecting the pathophysiological background underlying the progression of cardiorenal syndrome.

P235 CLINICAL AND INSTRUMENTAL CORRELATES OF LEFT AND RIGHT ATRIAL TWO–DIMENSIONAL STRAIN MEASUREMENTS IN PATIENTS WITH HEART FAILURE

Background

The two–dimensional strain obtained through Speckle Tracking Imaging (STI) represents an innovative, rapid and semi–automatic echocardiographic method to study systolic and diastolic function. By analyzing the deformation of cardiac segments, it provides an indirect index of myocardial contractility and relaxation of left and right ventricles, but also of both left and right atria.

Purpose of the Study

The aim of this study was to evaluate the clinical and instrumental correlates of the different measures of right and left atrial strain in a group of patients with chronic heart failure (CHF). Method. We enrolled 165 out patients with CHF (63 ± 14 years, 76% male, 39 ± 11% ejection fraction). All patients underwent a cardiological examination, ECG and echocardiogram. The echocardiographic images were analyzed using an innovative software (TomTec, Philips) able to semi–automatically analyze both the ventricular and atrial strain. For each patient, both for the left atrium (LA) and the right atrium (RA), the measures related to all atrial functional phases were calculated: reservoir (r), conduit (cd) and contraction (ct).

Results

At univariate and multivariate logistic regression models, the main determinants of atrial strain measurements were evaluated. As shown in the Table, both for the RA and LA the reservoir and conduit were more closely associated with ventricular systolic function and age. LA contraction was associated only with E/e‘ and heart rate, whereas for the RA one there was no independent statistical association with the parameters studied.

Conclusions

The Strain parameters that evaluate right and left atrial function have an independent association with different clinical and instrumental variables. These results support the hypothesis that the reservoir and conduit measurements express a different physiological and pathophysiological substrate than the contraction measures.

P233 ASSOCIATIONS BETWEEN LEFT AND RIGHT ATRIAL BIDIMENSIONAL STRAIN AND HEART FAILURE PROGRESSION

Background

Two dimensional speckle tracking is an innovative echocardiographic method which analyses myocardial deformation thus allowing the evaluation of both atrial and ventricular function. Recently, new software are available to measure it by semiautomatic analyses.

Aim of the Study

To evaluate the association between left and right atrial Strain and the occurrence of clinical events related to the heart failure (HF) progression. Method. We enrolled 165 outpatients with chronic HF (76% males, NYHA 2.2 ± 0.69, ejection fraction 39±11%). All underwent a clinical and echocardiographic evaluation. An innovative software (TomTec, Philips) was used to analyse the images in order to semi–automatically calculate of atrial Strain. For each patient all the measures relative to the different phases of atrial deformation were considered both for the left atrium (LA) and the right one (RA), i.e. reservoir (r), conduit (cd) and contraction (ct). During the follow–up, we defined the HF progression as hospitalization due to HF worsening and/or heart transplantation and/or cardiovascular death.

Results

During a median follow–up of 5 months, at least one event related to HF progression occurred in 22 patients: all underwent at least one hospitalization, 7 patients died because of cardiovascular reasons and 2 underwent heart transplantation. At Cox univariate analysis, LASr (HR: 0,93; 95%CI: 0,88–0,97, p: 0.004; C–index 0,7), LAScd (HR: 1,09; 95%CI: 1,01–1,19; p: 0,023; C–index: 0,64), RASr (HR: 0,95; 95%CI: 0,90–0,99; p: 0,031; C–index: 0,68), RAScd (HR: 1,08; 95%CI: 1,01–1,15; p: 0,021; C–index: 0,67), but not LASct (HR: 1,04; 95%CI: 0,99–1,09; p 0,094; C–index 0,62) and RASct (HR: 1,02; 95%CI: 0,96–1,09; p: 0,61; C–index: 0,55), were significantly associated to HF progression. LASr and RASr showed the higher accuracy in predicting the events by the estimation of C index. At ROC curve analysis, for LASr the best cut–off was 16.1% (Sensitivity 83%, Specificity 56%) and for RASr 17.3% (Sensitivity 79%, Specificity 60%). Figure shows Kaplan–Meier curves for the considered end–point according with these cut–offs.

Conclusions

The preliminary results of this study have showed the association between LA and RA Strain variables and the HF progression. The prosecution of this study will be finalised to demonstrate the prognostic independent and incremental significance.

P216 RENAL RESISTANCE INDEX IS INDEPENDENTLY ASSOCIATED WITH THE WORSENING OF RENAL FUNCTION AFTER CORONARY ANGIOGRAPHY

Background

The term Cardiorenal Syndrome (CS) has been recently introduced to indicate the close relationship between cardiovascular and renal diseases, which are able to reciprocally influence the each other progression. In this setting the renal resistance index (RRI) has been demonstrated to be a useful parameter able to detect patients at higher risk of CS. However, there are no data about its role in predicting worsening of renal function (WRF) mediated by the intravascular administration of contrast.

Aim of the Study

To evaluate the role of RRI in predicting WRF after coronary angiography. METHODS We enrolled 115 patients (mean age 64 years, 73% males, 84% hypertensive, 43% diabetic, 30% with acute coronary syndrome, 21% affected by chronic heart failure, CHF, with a mean left ventricular ejection fraction, LVEF, of 51±11) with suspected coronary artery disease, stable angina, or acute coronary syndromes who have been referred for coronary angiography (with or without pre–existing renal impairment). All patients underwent medical examination, electrocardiogram, echocardiographic and chemical evaluation, and renal arterial echo–color Doppler used to calculate RRI. WRF was defined as an increase of creatinine >0.3 mg/dl and of at least 25% from baseline 24–48 hours after coronary angiography.

Results

After coronary angiography, 14 (12%) of the enrolled patients showed WRF. As shown in the Table, at univariate regression analysis baseline RRI was associated with WRF as well as age, peripheral artery disease, CHF, atrial fibrillation, NYHA class, LVEF, mitral regurgitation (MR), central venous pressure (CVP), tricuspid regurgitation (TR), estimated glomerular filtration rate (GFR). In a multivariate forward stepwise regression model, including all univariate predictors, history of CHF, high CVP and RRI were the only parameters significantly associated with WRF.

Conclusion

Our findings demonstrate that in patients undergoing coronary angiography, history of CHF, high CVP and RRI are independent predictors of WRF. RRI, but not GFR, is independently associated with WRF probably because providing additional relevant information about cardiorenal pathophysiological factors reflecting the hemodynamic status and kidney flow reserve.