Doppler-derived dP/dt and -dP/dt predict survival in congestive heart failure

Left ventricular lead electrical delay predicts response to cardiac resynchronization therapy

BACKGROUND

Intracardiac electrograms can be used to guide left ventricular (LV) lead placement during implantation of cardiac resynchronization therapy (CRT) devices. Although attempts often are made to ensure that the LV lead is positioned at a site of maximal electrical delay, information on whether this is useful in predicting the acute hemodynamic response and long-term clinical outcome to CRT is limited.

OBJECTIVES

The purpose of this study was to assess the ability of intracardiac (electrogram) measurements made during LV lead placement in patients undergoing CRT for predicting acute hemodynamic response and long-term clinical outcome to CRT.

METHODS

Seventy-one subjects with standard indications for CRT underwent electrogram measurements and echocardiograms performed in the acute phase of this study. The LV lead electrical delay was measured intraoperatively from the onset of the surface ECG QRS complex to the onset of the sensed electrogram on the LV lead, as a percentage of the baseline QRS interval. Echocardiographic assessment of the hemodynamic response to CRT was measured as an intra-individual percentage change in dP/dt over baseline (DeltadP/dt, derived from the mitral regurgitation Doppler profile) with CRT on and off. dP/dt was measurable in 48 subjects, and acute responders to CRT were defined as those with DeltadP/dt >or=25%. Long-term response was measured as a combined endpoint of hospitalization for heart failure and/or all cause mortality at 12 months. Time to the primary endpoint was estimated by the Kaplan-Meier method, with comparisons made using the log rank test.

RESULTS

LV lead electrical delay correlated weakly with DeltadP/dt of the combined group (n = 48, r = 0.311, P = .029) but was strongly correlated with DeltadP/dt in the nonischemic subgroup (n = 20, r = 0.48, P = .027). LV lead electrical delay (%) was significantly longer in acute responders (69.6 +/- 23.9 vs 31.95 +/- 11.57, P = .002) among patients with nonischemic cardiomyopathy. A reduced LV lead electrical delay (<50% of the QRS duration) was associated with worse clinical outcome within the entire cohort (hazard ratio: 2.7, 95% confidence interval: 1.17-6.68, P = .032) as well as when stratified into ischemic and nonischemic subgroups.

CONCLUSION

Measuring LV lead electrical delay is useful during CRT device implantation because it may help predict hemodynamic response and long-term clinical outcome.

Plasma adrenomedullin relation with Doppler-derived dP/dt in patients with congestive heart failure

BACKGROUND

Increased circulating adrenomedullin (AM) concentration has been reported in congestive heart failure (HF) and considered as a possible marker of cardiac dysfunction.

HYPOTHESIS

The study was undertaken to assess the relationship between circulating AM concentration and left ventricular (LV) functional state, estimated by echo-Doppler techniques in patients with mild to moderate HF and different degrees of LV dysfunction.

METHODS

Plasma AM, B-type natriuretic peptide (BNP), and N-terminal (NT) proBNP levels were measured in 55 patients with HF (New York Heart Association [NYHA] I n = 8, II n = 26, III n = 21) and in 20 controls; dP/dt was calculated by the Doppler tracing of the mitral regurgitation jet.

RESULTS

The study was completed in 51 patients. Adrenomedullin levels were higher than in controls (19.2 +/- 1.4 vs. 13.3 +/- 0.7, p < 0.005) and elevated in proportion to NYHA functional class. B-type natriuretic peptide and NT-proBNP were 344 +/- 67 vs. 12 +/- 2 pg/ml and 2196 +/- 623 vs. 52 +/- 4 pg/ml, respectively (p < 0.0001); dP/dt was better related to AM (r = 0.582, p < 0.001) than to the other peptides. Adrenomedullin was significantly (p < 0.001) different between patients grouped according to the dP/dt cut-off predictive of event-free survival.

CONCLUSIONS

The combination of depressed contractility and increased AM may provide a clue for further characterization of the severity of LV dysfunction in HF, independent of baseline LV ejection fraction.

Usefulness of a novel "response score" to predict hemodynamic and clinical outcome from cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is an important treatment for patients with congestive heart failure and ventricular dyssynchrony, but response to CRT is highly variable. We assessed whether a scoring system that encompasses a combination of patient selection and procedural variables would improve prediction of CRT response. Thirty-nine patients who underwent CRT with echocardiographic assessment of baseline contractility and left ventricular (LV) dyssynchrony, intraprocedural assessment of LV lead electrical delay, and postprocedural chest radiography were included. Baseline LV dyssynchrony was measured by Doppler tissue velocity imaging as the maximum time difference between peak systolic velocity of anterior, lateral, posterior, and septal walls. The hemodynamic effect of CRT was measured by Doppler analysis of mitral regurgitation as percent change in maximal +dP/dt (DeltadP/dt) with CRT on versus off. Acute responders to CRT were defined as Deltadp/dt >or=25%. Clinical response was measured as a combined end point of hospitalization for heart failure and all-cause mortality. A 4-point response score was generated using variables associated with DeltadP/dt and assigning 1 point for a dorsoventral LV/right ventricular interlead distance>10 cm, 1 point for a LV lead electrical delay>or=50%, 1 point for a baseline maximum +dP/dt <600 mm Hg/s, and 1 point for a maximum time difference>100 ms. In conclusion, there was a significant association between response score (0 to 4 points) and acute hemodynamic response to CRT (p<0.0001). Kaplan-Meier analysis associated a higher response score with improved 12-month event-free survival after CRT implantation (p=0.0019).

Left Ventricular Lead Proximity to an Akinetic Segment and Impact on Outcome of Cardiac Resynchronization Therapy

BACKGROUND

Previous studies report that the optimal pacing site for cardiac resynchronization therapy (CRT) is along the left ventricular (LV) lateral and postero-lateral (PL) wall. However, little is known regarding whether pacing over an akinetic site impacts the contractile response and long-term outcome from CRT.

METHODS AND RESULTS

A total of 38 patients with ischemic cardiomyopathy were studied for their acute hemodynamic and 12-month clinical response to CRT. The intraindividual percentage change in dP/dt (%DeltadP/dt), over baseline, was derived from the mitral regurgitation (MR) Doppler profile with CRT on versus off. Two-dimensional echocardiography was used for myocardial segmentation and determinination of akinetic sites. LV lead implant site was determined using angiographic and radiographic data and categorized as being "on" (group 1) or "off" (group 2) an akinetic site. Long-term response was measured as a combined endpoint of hospitalization for heart failure and/or all cause mortality at 12 months. Time to primary endpoint was estimated by the Kaplan-Meier method. Clinical characteristics and acute hemodynamic response was similar in both (group 1 [n = 14]; %DeltadP/dt 48.8 +/- 67.4% vs group 2 [n = 24]; %DeltadP/dt 32.2 +/- 40.1%, P = 0.92). No difference in long-term outcome was observed (P = 0.59). In contrast, lead placement in PL or mid-lateral (ML) positions was associated with a better acute hemodynamic response when compared to antero-lateral (AL) positions (PL, %DeltadP/dt 45.7 +/- 50.7% and ML, %DeltadP/dt 45.1 +/- 58.8% vs AL, %DeltadP/dt 2.9 +/- 30.9%, respectively, P = 0.014).

CONCLUSION

LV lead proximity to an akinetic segment does not impact acute hemodynamic or 12-month clinical response to CRT.

Prognostic Value of Pacing-Induced Mechanical Alternans in Patients With Mild-to-Moderate Idiopathic Dilated Cardiomyopathy in Sinus Rhythm

OBJECTIVES

The relation between the occurrence of pacing-induced mechanical alternans and prognosis in patients with mild-to-moderate idiopathic dilated cardiomyopathy (IDCM) in sinus rhythm was investigated prospectively. The myocardial expression of genes for Ca2+-handling proteins in such patients was also examined.

BACKGROUND

Mechanical alternans occurs in some patients with severe heart failure, but the relation between the occurrence of mechanical alternans and prognosis in patients with IDCM has remained unknown.

METHODS

Left ventricular (LV) pressure was measured during atrial pacing, and LV endomyocardial biopsy specimens were collected in 36 IDCM patients and 8 controls. Idiopathic dilated cardiomyopathy patients were divided into two groups consisting of 22 individuals who did not develop mechanical alternans at heart rates up to 140 beats/min (group A) and of 14 individuals who did (group B). The patients were followed up for a mean of 3.7 years.

RESULTS

There was no significant difference in LV ejection fraction or the plasma concentration of brain natriuretic peptide between groups A and B. The myocardial abundance of ryanodine receptor 2 messenger ribonucleic acid (mRNA) was significantly lower in groups A and B than in controls, whereas that of sarcoplasmic reticulum Ca2+-ATPase mRNA was significantly lower in group B than in group A or controls. Stepwise multivariate analysis identified pacing-induced mechanical alternans as the strongest predictor of cardiac events. Event-free survival in group A was significantly greater than that in group B.

CONCLUSIONS

The occurrence of pacing-induced mechanical alternans is a potentially useful indicator of poor prognosis in patients with mild-to-moderate IDCM in sinus rhythm.

Effect of dynamic left ventricular dyssynchrony on dynamic mitral regurgitation in patients with heart failure due to coronary artery disease

In patients with heart failure, exercise-induced increases in mitral regurgitation (MR), which convey a poor prognosis, are related to the dynamic distortion of mitral valve geometry. It was hypothesized that dynamic MR may also be related to intermittent changes in left ventricular synchronicity during exercise.

Contractile response and mitral regurgitation after temporary interruption of long-term cardiac resynchronization therapy

AIMS

Cardiac resynchronization therapy (CRT) utilizing biventricular pacing (BVP) is a promising treatment modality for symptomatic patients with chronic left ventricular (LV) systolic dysfunction and intraventricular conduction delay. Clinical studies have shown short-term improvement in contractile function and mid-term improvement in clinical status with CRT. The objective of this study was to evaluate the haemodynamic consequences of temporary interruption of CRT after long-term stimulation.

METHODS AND RESULTS

Twenty patients (16 men, 4 women) with LV dysfunction and New York Heart Association class III or IV heart failure, despite optimal medical therapy and a QRS interval of at least 120 ms, received a transvenous BVP system at the age of 66 (interquartile range, 61-69). Patients were studied after a median duration of 427 days (interquartile range, 281-563) of continuous CRT and again 72 h after cessation of BVP. Withdrawal of CRT resulted in a significant decline in maximal rate of LV systolic pressure rise from 711 mmHg/s (interquartile range, 640-816) to 442 mmHg/s (interquartile range, 389-582) (P=0.0001) and increases in mitral effective regurgitant orifice area from 4.8 mm(2) (interquartile range, 0.0-7.8) to 9.1 mm(2) (interquartile range, 5.7-13.3) (P=0.0001), mitral regurgitant volume from 7.8 mL (interquartile range, 0.0-11.5) to 16.0 mL (interquartile range, 10.7-20.8) (P=0.0001) and fraction from 13.8% (interquartile range, 0.0-19.2) to 27.7% (interquartile range, 14.6-34.0) (P=0.0002) determined by Doppler echocardiography.

CONCLUSION

Cessation of long-term BVP leads to a decline in LV systolic performance and an increase in functional mitral regurgitation. These results indicate a sustained benefit of long-term CRT and support the notion to maintain CRT indefinitely.

Radiographic left ventricular-right ventricular interlead distance predicts the acute hemodynamic response to cardiac resynchronization therapy

Placement of left ventricular (LV) and right ventricular (RV) leads with maximal interlead separation is frequently sought during cardiac resynchronization therapy (CRT), but few published data are available to support this. This study examined the relation between LV and RV lead separation and the acute effects of CRT on cardiac contractility. A total of 51 consecutive patients who underwent CRT for standard indications with sufficient mitral regurgitation for echocardiographic assessment of contractility (using Doppler profiles of mitral regurgitation as a percentage of change in dP/dt [DeltadP/dt] with CRT on and off), successful transvenous LV lead placement, and postprocedural chest radiography were evaluated. The separation of the LV and RV lead tips (direct interlead distance and horizontal and vertical components) was determined on postprocedural posteroanterior and lateral radiographs. The corrected direct LV-RV interlead distance on the lateral radiograph was correlated with the DeltadP/dt (n = 51, r = 0.43, p = 0.002). The lateral interlead distance in the horizontal plane (r = 0.58, p <0.0001), but not the vertical plane (r = -0.28, p = NS), correlated with the DeltadP/dt. The corrected horizontal interlead distance on the lateral film was greater in acute hemodynamic responders to CRT (DeltadP/dt >25%) compared with nonresponders (14.4 +/- 5.4 vs 9.2 +/- 5.8 cm, p = 0.002). Other LV-RV measures on the posteroanterior and lateral radiographs did not correlate with the DeltadP/dt. Use of these findings may help to guide the sites of LV and RV lead placement to maximize the benefit derived from CRT.

A Novel Method to Estimate Pulmonary Artery Wedge Pressure Using the Downslope of the Doppler Mitral Regurgitant Velocity Profile

Continuous-wave (CW) Doppler recording of mitral regurgitation (MR) is a reflection of the left ventriculoatrial pressure gradient. Accordingly, this jet may yield information about pulmonary artery wedge pressure (PAWP). In this study, we derived and then evaluated a novel method for prediction of PAWP. Patients (n=80) with moderate to severe MR and left ventricular dysfunction were included in the study. Transthoracic echocardiography was performed in patients during pulmonary artery pressure monitoring. A satisfactory CW Doppler recording of MR was obtained in 63/80 (78%). On the late descending portion of the CW recording, the time from a velocity of 4 m/sec to the end of the jet was defined as t1, and from 3 m/sec to the end of the jet as t2. Mathematical derivation of t1/t2 as a predictor of PAWP, was performed based on Weiss' derivation. If t1/t2 was <1.30, the PAWP was normal. If t1/t2 > 1.44, the PAWP was > 16 mmHg. With this new mathematical derivation, it appears that the downslope of the CW Doppler MR waveform may be able to distinguish a normal from elevated PAWP.

Hcc-1 is a novel component of the nuclear matrix with growth inhibitory function

Hcc-1 is a novel nuclear protein containing the SAF-box DNA-binding domain. It binds to both double-stranded and single-stranded DNA with higher affinity for the single-stranded form. In addition, it also binds specifically to scaffold/matrix attachment region DNA. These nucleic acid-binding characteristics suggest a potential function for Hcc-1 as a component of the heterogeneous ribonucleoprotein complex. Using a yeast two-hybrid screen, two DEAD-box RNA helicases, BAT1 and DDX39, were identified as proteins that interact with Hcc-1. Interactions with these RNA helicases suggested a role for Hcc-1 in nucleic acid biogenesis. Expression of Hcc-1 in the HEK293 cell line resulted in a slower growth rate compared to controls (p = 0.0173) and an accumulation of cells at the G2/M phase (p = 0.0276 compared to control HEK293 cells). Taken together, these results suggest a role for Hcc-1 in growth regulation and nucleic acids metabolism.

Use of tissue Doppler echocardiography in early detection of left ventricular systolic dysfunction in patients with mitral regurgitation

OBJECTIVE

Left ventricular ejection fraction (EF) and left ventricular (LV) end-systolic diameter measurements are the most widely accepted and utilized methods to demonstrate LV dysfunction in patients with mitral regurgitation (MR). However, these parameters still have many drawbacks in predicting early LV dysfunction. This study investigates the clinical usefulness of tissue Doppler echocardiography technique in detecting early disturbance of myocardial contractility in asymptomatic patients with chronic, severe MR and normal LV ejection fraction values.

METHODS AND RESULTS

Regional systolic peak velocities of mitral annular motion during the ejection phase of systole (SW2) were obtained at the mitral annuli of the ventricular septal, lateral, anteroseptal, posterior, anterior and inferior wall sites in the long axis in 31 asymptomatic patients with severe MR (with a regurgitant volume of more than 50 ml) and with EFs more than 60%. The patients were grouped according to their dP/dt values (more or less than 1300 mmHg/s) estimated non-invasively by using continuous Doppler wave of MR SW2 measurements of Group I were higher than Group II in all of the analyzed segments. The difference was statistically significant for all of the segments. SW2 values of the whole study group was moderately correlated with dP/dt measurements in all of the analyzed segments other than the interventricular septum.

CONCLUSION

SW2 measurements in the long axis, which are considered to be relatively independent from afterload conditions may be helpful in early detection (while EF is still in normal range) of LV systolic dysfunction during the follow-up of patients with chronic MR.

Prognostic value of mechanical efficiency in ambulatory patients with idiopathic dilated cardiomyopathy in sinus rhythm

OBJECTIVES

The purpose of this study was to determine, by analyzing the pressure-volume relationship, the prognostic value of parameters related to myocardial energetics for predicting mortality in patients with dilated cardiomyopathy (DCM) in sinus rhythm.

BACKGROUND

The relationship between the myocardial energetics and the prognosis of patients with DCM in sinus rhythm remains unclear.

METHODS

We followed 114 ambulatory patients with nonischemic DCM in sinus rhythm for a mean period of 5.8 +/- 3.9 years. Over 70% of our patients were in New York Heart Association functional class I and class II. Pressure-volume data were obtained by the conductance method, and myocardial oxygen consumption per beat (VO(2)) measurements were obtained.

RESULTS

The 3-, 5-, and 10-year cumulative survival rates were 88.6%, 80.0%, and 73.9%, respectively. Of the 114 patients, 47 were selected randomly to assess their myocardial energetics. By univariate analysis, the mechanical efficiency (ME, external work/VO(2)), left ventricular (LV) ejection fraction and the LV end-diastolic pressure were statistically associated with cardiac death. The ME was the strongest predictor of survival in a Cox proportional-hazards analysis (p = 0.011). The best cutoff point of ME identified by the receiver-operating curve was 11%. This value had a sensitivity of 100%, a specificity of 87% and an overall predictive accuracy of 88% to distinguish survivors from nonsurvivors.

CONCLUSIONS

This study clearly demonstrates that ME is a powerful clinical predictor for cardiac death in patients with mild to moderate heart failure and with sinus rhythm. Whether these conclusions apply to patients with more severe heart failure requires further investigations.

Echocardiographic prediction of long-term response to biventricular pacemaker in severe heart failure

BACKGROUND

Biventricular pacing substantially improves LV systolic function and symptom status in some patients with dilated cardiomyopathy.

AIMS

To assess whether the long-term benefit could be predicted from the echocardiographic parameters.

METHODS AND RESULTS

Sixteen patients with dilated cardiomyopathy who underwent atrio-biventricular pacemaker implantation were analyzed in two groups: the responders (n=11) were those with a symptomatic improvement of one or more NYHA functional class; the non-responders (n=5) failed to improve at follow-up (7.6+/-5 months). Echocardiography was performed at baseline, the day after the implantation and then every 3 months. Besides the conventional parameters, the following variables were included: LV diastolic filling time (DFT); the duration of mitral regurgitation (dMR); and LV dP/dt obtained from the continuous wave mitral regurgitation curve. While the baseline DFT and dP/dt were not significantly different between non-responders and responders (256+/-105 vs. 358+/-115, P=0.14 and 564+/-199 vs. 468+/-117, P=0.44, respectively), the QRS width (149+/-15 vs. 175+/-24 ms, P=0.05) and the dMR (343+/-70 vs. 443+/-49 ms, P=0.007) were higher in the responders. The changes of dMR, DFT and QRS width by pacing were not significantly different between groups (P=0.18, 0.30 and 0.77, respectively). However, the change of LV dP/dt by pacing in the responders was significantly different than for non-responders (from 468+/-117 to 676+/-216 mmHg/s vs. from 564+/-199 to 483+/-94, P=0.002). An acute increase in LV dP/dt over 22% by pacing yielded only two false negatives and no false positives in predicting the long-term responsiveness.

CONCLUSION

Patients with longer QRS and dMR are more likely to benefit from atrio-biventricular stimulation. The acute changes of Doppler derived LV dP/dt may provide valuable information in predicting the long-term response to biventricular pacing.