Ventricular arrhythmias in dilated cardiomyopathy as an independent prognostic hallmark. Italian Multicenter Cardiomyopathy Study (SPIC) Group

Perioperative ventricular dysrhythmias in patients with structural heart disease undergoing noncardiac surgery

Noncardiac surgical patients with preoperative ventricular dysrhythmias and structural heart disease may be at increased risk of adverse cardiac outcome. We evaluated how anesthesia and surgery affect the course of ventricular dysrhythmias (premature ventricular beats [PVB] and repetitive forms of ventricular beats [RFVB]: couplets and nonsustained ventricular tachycardia) noted preoperatively in patients with structural heart disease and whether the frequency of ventricular dysrhythmias affects cardiac outcome. In a prospective study, 70 patients scheduled for noncardiac surgery with structural heart disease and RFVB on preoperative Holter electrocardiogram were continuously monitored intraoperatively and for 3 days postoperatively. Holter tracings were analyzed for rhythm, medians of total PVB and RFVB per hour. Preoperative RFVB recurred intraoperatively in 35% and postoperatively in 87% of patients. There was a significant intra- and postoperative decrease of total PVB per hour (P < 0.05) and RFVB per hour (P < 0.01). Frequency of ventricular dysrhythmias in the five patients suffering adverse outcome (unstable angina, n = 1; congestive heart failure, n = 4) did not significantly differ from those with good outcome. We conclude that in noncardiac surgical patients with structural heart disease and RFVB, the frequency of ventricular dysrhythmias is not associated with adverse cardiac outcome.

IMPLICATIONS

Using continuous electrocardiogram monitoring, we investigated whether the frequency of perioperative ventricular dysrhythmias independently affects outcome in patients with structural heart disease undergoing noncardiac surgery. The incidence of perioperative dysrhythmia in patients with an adverse outcome (8%) did not differ from those with a good outcome.

Comparison of mortality rates and progression of left ventricular dysfunction in patients with idiopathic dilated cardiomyopathy and dilated versus nondilated right ventricular cavities

This study assesses the influence of right ventricular (RV) dilation on the progression of left ventricular (LV) dysfunction and survival in patients with idiopathic dilated cardiomyopathy (IDC). Using transthoracic echocardiography, we studied 100 patients with IDC aged 20 to 80 years (mean 55 +/- 14); 67% were men. In the apical 4-chamber view, diastolic LV and RV chamber area measurements classified patients into 2 groups: group RV enlargement+ (RV area/LV area > 0.5) included 54 patients; group RV enlargement- (no RV enlargement) had RV area/LV area < or = 0.5. Echocardiographic studies were repeated in all patients after a mean of 33 +/- 16 months. At the time of the initial study, the 2 groups did not differ in age, gender, incidence of atrial fibrillation and diabetes, left ventricular mass, and LV ejection fraction, but the RV enlargement+ group had more severe tricuspid regurgitation and less LV enlargement. After 47 +/- 22 months (range 12 to 96), patients in group RV enlargement+ had lower LV ejection fraction (29% vs 34%, p = 0.006) than patients with initial RV enlargement-. At clinical follow-up, mortality was higher (43%) in patients with initial RV enlargement+ than the RV enlargement- patients (15%), p = 0.002. For survivors, the mitral deceleration time averaged 157 +/- 36 ms; for nonsurvivors or patients who required transplant, the mitral deceleration time averaged 97 +/- 12 ms (p < 0.0001). With use of a multivariate Cox model adjusting for LV ejection fraction, LV size, and age, the relative risk ratio of mortality from initial RV enlargement+ was 4.4 (95% confidence limits 1.7 to 11.1) (p = 0.002). Thus, patients with significant RV dilation had nearly triple the mortality over 4 years and more rapidly deteriorating LV function than patients with less initial RV dilation. In IDC, RV enlargement is a strong marker for adverse prognosis that may represent a different morphologic subset.

Ventricular arrhythmias in dilated cardiomyopathy

Although prognosis of dilated cardiomyopathy (DCM) has improved due to advances in diagnosis and therapy, still too many sudden cardiac deaths occur in DCM. Spontaneous ventricular ectopy is a very common finding in patients with DCM, but the prognostic significance of Holter monitoring remains controversial. Other noninvasive methods, e.g., late potentials and QT dispersion, have not yet contributed to the evaluation of prognosis for arrhythmogenic events in DCM. Programmed ventricular stimulation has been repeatedly used to stratify long-term prognosis, yet satisfactory data are still missing as many deaths occur in patients without inducible arrhythmias. Several prognostic studies are still in progress, and preliminary data for the use of ICDs already appear to be promising. In patients with poor left ventricular function and ICDs in situ, prognosis is determined by progression of heart failure. Heart transplantation may be the ultimate therapeutic instrument for end-stage heart failure patients. For patients with advanced DCM and increased risk for malignant arrhythmias who are unsuitable for orthotopic heart transplantation, the combined therapy with an ICD and dynamic cardiomyoplasty may be an alternative treatment.

Persistence of restrictive left ventricular filling pattern in dilated cardiomyopathy: an ominous prognostic sign

OBJECTIVES

We sought to assess the prognostic implications of the evolution of restrictive left ventricular filling pattern (RFP) in dilated cardiomyopathy (DCM).

BACKGROUND

Previous work has demonstrated that a RFP in DCM is associated with a poor prognosis. Few data are available on the prognostic implications of the evolution of this pattern.

METHODS

The evolution of left ventricular filling was studied by Doppler echocardiography in 110 patients with DCM. According to the left ventricular filling pattern at presentation and after 3 months of treatment, the patients were classified into three groups: Group 1A (n = 24) had persistent restrictive filling; Group 1B (n = 29) had reversible restrictive filling; and Group 2 (n = 57) had nonrestrictive filling.

RESULTS

During follow-up (41 +/- 20 months), mortality plus heart transplantations was significantly higher in Group 1A than in Groups 1B and 2 (p < 0.0001). On multivariate analysis, the model incorporating E wave deceleration time at 3 months was more powerful at predicting mortality with respect to this variable at baseline (p = 0.0039). Clinical improvement at 1 and 2 years was significantly more frequent in Groups 1B and 2 than in Group 1A (p < 0.0001 at 2 years).

CONCLUSIONS

In patients with DCM, the persistence of restrictive filling at 3 months is associated with a high mortality and transplantation rate. The patients with reversible restrictive filling have a high probability of improvement and excellent survival. Doppler echocardiographic reevaluation of these patients after 3 months of therapy gives additional prognostic information with respect to the initial study.

Predictors of sudden death and death from pump failure in congestive heart failure are different. Analysis of 24 h Holter monitoring, clinical variables, blood chemistry, exercise test and radionuclide angiography

One hundred and ninety consecutive patients discharged with congestive heart failure were examined with clinical evaluation, blood chemistry, 24 h Holter monitoring, exercise test and radionuclide angiography. Median left ventricular ejection fraction was 0.30, 46% were in New York Heart Association class II and 44% in III. Total mortality after 1 year was 21%, after 2 years 32%. Of 60 deaths, 33% were sudden and 49% due to pump failure. Multivariate analyses identified totally different risk factors for sudden death: ventricular tachycardia, s-sodium < or = 137 mmol/l, s-magnesium < or = 0.80 mmol/l, s-creatinine > 121 mumol/l, and maximal change in heart rate during exercise < or = 35 min-1, and for death from progressive pump failure: New York Heart Association class III + IV, delta heart rate over 24 h < or = 50 min-1, low ejection fraction, high resting p-noradrenaline, s-urea > 7.6 mmol/l, s-potassium < 3.5 mmol/l, and maximal exercise duration < or = 4 min. In conclusion, this study demonstrated different risk factors for sudden death and for death from progressive pump failure.

Comparison of time domain and spectral turbulence analysis of the signal-averaged electrocardiogram for the prediction of prognosis in idiopathic dilated cardiomyopathy

BACKGROUND

Despite significant advances in the treatment of heart failure, the prognosis of patients with idiopathic dilated cardiomyopathy remains poor. Although several of prognostic variables have been shown to be useful in risk stratification of patients with idiopathic dilated cardiomyopathy, their predictive accuracy is low and clinical usefulness uncertain.

HYPOTHESIS

This study was undertaken to assess the signal-averaged electrocardiogram (SAECG) in patients with idiopathic dilated cardiomyopathy and to compare the ability of time domain and spectral turbulence analytic techniques to predict clinical outcome.

METHODS

SAECG analysis was performed in 80 patients with idiopathic dilated cardiomyopathy. Nineteen patients had left bundle-branch block and eight were taking low-dose amiodarone for life-threatening arrhythmias. Conventional time domain and spectral turbulence analyses of the SAECG were performed using Del Mar 183 software.

RESULTS

During a follow-up of 27 +/- 19 months, 24 patients developed progressive heart failure, while the others remained clinically stable. Late potentials were detected in 28% of patients and were equally frequent in patients with and without progressive heart failure (38 vs. 23%, p = 0.20). Spectral turbulence analysis was abnormal in 34% of patients, and patients with abnormal results developed progressive heart failure more frequently than those with normal results (50 vs. 17%, p = 0.01). All spectral turbulence analysis parameters were significantly different in patients with progressive heart failure compared with those who remained clinically stable (p < or = 0.01). Furthermore, progressive heart failure-free survival at 2 years was significantly lower in patients with abnormal compared with normal results (63 vs. 87%; p < 0.05), but was similar in patients with and without late potentials (72 vs. 83%; p = 0.30). The relative risk for developing progressive heart failure using spectral turbulence analysis was 3.4 (95% confidence interval 1.2-9.7) and 2.8 (95% confidence interval 1.1-8.7) using time domain analysis. The sensitivity, specificity, and the positive and negative predictive accuracy for identifying patients who developed progressive heart failure were 50, 83, 50, and 83%, respectively, (p = 0.01) for spectral turbulence analysis, and 36, 85, 45 and 80%, respectively, (p = 0.09) for time domain analysis.

CONCLUSION

Abnormalities in the SAECG of patients with idiopathic dilated cardiomyopathy are common and appear to provide a noninvasive marker for development of progressive heart failure.

Determinants of prognosis in nonischemic dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy, a heart muscle disease of unknown cause, is characterized by high mortality and is a major cause of cardiac transplantation. It has become, therefore, increasingly important to identify patients at higher risk. The aim of this study was to assess which of the data obtained at the time of diagnosis are the best predictors of survival.

METHODS AND RESULTS

One hundred forty-four patients with dilated cardiomyopathy (118 men; mean age, 39 years) were assessed clinically, noninvasively, and hemodynamically. The effect of variables derived from the evaluation on outcome (death or heart transplantation) was examined. During a mean follow-up time of 4.1 years, 68 patients (47%) died and 9 (6%) underwent heart transplantation. The 1-, 2-, and 5-year transplant-free survival rate was 79, 69, and 44%, respectively. Cox multivariate regression analysis identified three variables as independent predictors of outcome: (1) pulmonary artery systolic pressure, P = .0001; (2) left ventricular ejection fraction, P = .0013; and (3) left ventricular end-diastolic dimension, P = .007. The prognostic index was constructed from regression coefficients and parameters significant in the Cox model. The minimal prognostic index in the study group was 1.4 and the maximal was 6.0 with a corresponding 1-year survival of 98 and 18%, respectively. The validity of the prognostic index was tested in the consecutive group of 81 patients, who were followed for a mean 2.3 years. The prognostic index of the poor outcome group differed significantly from that in survivors (3.7 vs 2.9, respectively, P < .01). The sensitivity and specificity of model predictions were 68 and 52%, respectively.

CONCLUSIONS

The severity of pulmonary hypertension and left ventricular dysfunction provides an independent insight into the prognosis of patients with dilated cardiomyopathy. The prognostic index is useful when assessing prognosis and may be helpful in the timing of heart transplantation.

Electrocardiographic predictors in the ESVEM trial: unsustained ventricular tachycardia, heart period variability, and the signal-averaged electrocardiogram

Sudden death remains a major problem because the causes are uncontrolled and accurate predictors have not been identified. However, new forms of electrocardiographic (ECG) analyses may provide prognostic information. The Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) trial provides a unique perspective to this issue because baseline and follow-up data were prospectively acquired on a relatively large sample of patients who were homogeneous with respect to sustained ventricular tachyarrhythmias, frequent ectopic activity, and inducible sustained ventricular tachyarrhythmias. Although analysis of the large amount of ECG data collected is in progress, initial studies have provided information about unsustained ventricular tachycardia (VTu), heart period (R-R) variability, and the signal-averaged ECG. VTu has been reported to have prognostic implications in several disorders, but its clinical significance in patients with sustained ventricular tachyarrhythmias is unknown. The significance of VTu recorded in the baseline (antiarrhythmic drug-free) 48-hour ECG recording in ESVEM study patients was examined; no variable representing the presence of VTu, the frequency of VTu events, or the duration of the longest episode of VTu was a significant predictor of arrhythmia recurrence, arrhythmic death, or all-cause mortality, although a trend was present for worse all-cause mortality in patients with VTu. R-R variability provides powerful prognostic information after acute myocardial infarction (AMI) and in patients with chronic ischemic heart disease. In general, R-R variability decreases dramatically at the time of AMI and recovers somewhat during the year after infarction. Although most patients in the ESVEM trial had chronic ischemic heart disease, R-R variability, which has been determined in about three fourths of the patients, was much lower than that reported in patients 1 year after MI. Instead, the mean values were closer to the more depressed values observed shortly after MI. This suggests a greater degree of autonomic dysfunction in patients with sustained ventricular tachyarrhythmias, frequent ventricular ectopic activity, and low ejection fractions, as compared with that for patients with chronic ischemic heart disease in general. Signal-averaged ECGs have also been shown to predict arrhythmic events in patients with ischemic heart disease. In a subset of the ESVEM patients, antiarrhythmic drugs that block sodium channels were found to prolong the filtered, signal-averaged QRS duration, especially the late potential portion. This correlated with prolongation of the cycle length of induced ventricular tachycardia. Sotalol appeared to have a differential effect on the signal-averaged ECG; the signal-averaged QRS shortened slightly in patients in whom induction of VT was suppressed by sotalol, whereas it appeared to lengthen slightly in patients in whom VT remained inducible despite sotalol. This suggests that sotalol may affect conduction in diseased tissue in some patients, and that this may affect suppression of ventricular arrhythmia induction by programmed stimulation.

Effect of low dose Amiodarone on the incidence of sudden death in elderly patients with congestive heart failure: a double-bind, placebo-controlled study

To determine if low-dose Amiodarone could reduce sudden death (SD) among patients with congestive heart failure, a prospective, double-blind, placebo-controlled study was conducted. The study group consisted of 46 patients (36 men and 10 women, mean age 71 +/- 5 years) with complex ventricular ectopy documented by 48-hour Holter monitoring. Randomization divided the patients into two treatment groups: the first group received Amiodarone (400 mg/day for 1 week and then 100 mg/day), while the second group received placebo. The drug significantly reduced ventricular arrhythmias, but then was no decrease in incidence of SD. This study demonstrates not only that low-dose Amiodarone can be safely administered to elderly patients with congestive heart failure and it will significantly suppress ventricular arrhythmias, but also that reduction in ventricular arrhythmias and the risk of SD are not linearly related.

Radiofrequency catheter ablation of sustained ventricular tachycardia in idiopathic dilated cardiomyopathy

BACKGROUND

The feasibility of radiofrequency (RF) catheter ablation for the treatment of sustained ventricular tachycardia (VT) in patients with coronary artery disease and remote myocardial infarction has recently been demonstrated. At present, therapeutic options for VT in patients with idiopathic dilated cardiomyopathy (DCM) include antiarrhythmic drugs and implantable cardioverter/defibrillators (ICD). The purpose of the present study was to investigate the feasibility of RF catheter ablation in patients with idiopathic DCM who could not be adequately treated by conventional treatment modalities because of incessant or frequent, recurrent VT.

METHODS AND RESULTS

RF current application for ablation of 9 VTs (mean cycle length, 402 +/- 78 ms) was attempted in 8 patients with idiopathic DCM (4 men, 4 women; mean age, 54 +/- 6 years; mean left ventricular ejection fraction, 30 +/- 9%). Inclusion criteria for ablation were incessant VT (n = 4) or frequent, recurrent VT reproducibly inducible with programmed electrical stimulation (n = 5). Three patients had suffered aborted sudden cardiac death, and 2 had experienced syncope. Two patients were artificially ventilated and catecholamine dependent for hemodynamic reasons at the time of attempted ablation. Potential target sites for RF current application were identified by detailed endocardial mapping during sinus rhythm, activation and entrainment mapping during VT, and pace mapping. After 7 +/- 5 RF pulses (range, 2 to 18 pulses; median, 6 pulses) applied with 32 +/- 7 W for 39 +/- 9 seconds, 6 of the 9 target VTs (67%) were rendered noninducible (4 of 4 incessant VTs and 2 of 5 chronic recurrent VTs). In 6 patients, VTs with ECG morphologies other than the target VTs were inducible after RF catheter ablation. Seven patients were on antiarrhythmic drugs during the ablation procedure and during the follow-up period of 8 +/- 5 months (range, 2 to 17 months). One patient received an ICD before RF ablation, 4 patients after RF ablation, and 1 patient after ablation of an incessant VT and before attempted ablation of frequent, recurrent VTs. One patient underwent heart transplantation 5 months after ablation in end-stage heart failure. There were no acute complications during the mapping and ablation procedure. During the follow-up period, 1 patient had been resuscitated from ventricular fibrillation 6 weeks after ablation and finally died of congestive heart failure 2 weeks later. No further episodes of incessant VT occurred in the patients who had undergone RF current application for ablation of incessant VT. A complete prevention of VT could be achieved in 2 of 8 patients, whereas in 5 patients, VT episodes were stored in the ICD devices during follow-up.

CONCLUSIONS

The results of the present study indicate that RF current application for ablation of VT in a select group of patients with idiopathic DCM is feasible. The efficacy of RF ablation may be high in patients presenting with incessant VT, whereas the success rate seems to be only moderate in patients with chronic recurrent VT. In all patients, additional treatment options, including antiarrhythmic drugs, ICDs, and/or heart transplantation, were applied after RF ablation, indicating that RF ablation for this indication may be an adjunctive and not a curative treatment option.

Prognostic importance of the length of ventricular tachycardia in patients with nonischemic congestive heart failure

In patients with congestive heart failure the frequency of ventricular arrhythmias poorly predicts mortality. It is unknown whether the length of ventricular tachycardia is a better predictor of mortality in these patients. We therefore investigated the prognostic importance of the length of the longest run of ventricular tachycardia, the frequency of ventricular tachycardia, and the frequency of ventricular premature depolarizations with 24-hour ambulatory electrocardiographic recordings in 122 patients with heart failure. We also determined whether the cause of heart failure affects the prognostic importance of these parameters. Each ambulatory electrocardiographic recording was evaluated for the frequency of ventricular premature depolarizations and ventricular tachycardia and for the length of the longest run of ventricular tachycardia. For each electrocardiographic parameter patients were divided into groups based on the median value of that parameter. Mortality among groups was compared in all patients and then separately for nonischemic and ischemic patients. Neither the frequency of ventricular premature depolarizations nor the frequency of ventricular tachycardia predicted mortality whether or not cause was considered. When all patients were examined, the length of ventricular tachycardia did predict an increased risk of death. However, when cause was considered, length of ventricular tachycardia predicted mortality only in the nonischemic patients and not in the ischemic patients. We conclude that the length of ventricular tachycardia may be the best electrocardiographic predictor of mortality in patients with nonischemic heart failure.

The impact of implantable cardioverter-defibrillators on mortality among patients on the waiting list for heart transplantation

Implantable cardioverter-defibrillators were investigated for their impact on mortality in 228 consecutive heart transplant candidates on the waiting list for transplantation (207 patients without and 21 with implantable cardioverter-defibrillator therapy). The mortality rate in 207 patients without implantable cardioverter-defibrillator therapy was 23.2% and in 21 patients with implantable cardioverter-defibrillator therapy was 4.7%. In a Cox proportional hazards model for all 228 study patients (mortality while on the waiting list: 21.5%; transplantation rate: 54.8%), the absence of an implantable cardioverter-defibrillator was only a marginally significant predictor of mortality (p = 0.079). However, the absence of an implantable cardioverter-defibrillator was a powerful predictor of mortality for a subgroup of 134 patients with high-grade ventricular arrhythmias on Holter electrocardiography (mortality while on the waiting list: 26.1%; transplantation rate: 54.5%; p = 0.022) and for a subgroup of 58 survivors of sudden cardiac death (mortality while on the waiting list: 22.4%; transplantation rate: 56.9%; p = 0.018). Implantable cardioverter-defibrillator therapy can be strongly recommended in transplant candidates with a history of sudden cardiac death. Recommendations for an expanded, prophylactic use of implantable cardioverter-defibrillator therapy in heart transplant candidates cannot be given.

Long-term outcome and prognostic factors in dilated cardiomyopathy. Preliminary results

To investigate long-term follow-up and identify prognostic factors in patients with dilated cardiomyopathy (DCM) the authors investigated 167 consecutive patients on an outpatient basis. All patients underwent left- and right-heart catheterization; follow-up comprised clinical and echocardiographic investigations.

RESULTS

After a mean follow-up period of ninety-three +/- thirty-six months 82 patients (49%; 71 men, 11 women, mean age fifty-five +/- eleven years) were alive. 29 of them (27 men, 2 women, mean age fifty-two +/- nine) showed normal left ventricular ejection fraction (LVEF) after a mean follow-up period of one hundred four +/- forty months. The remaining 53 patients (44 men, 9 women, mean age fifty-six +/- eleven) revealed LVEF similar to that of the first examination. Eighty-five patients died (51%; 73 men, 12 women). Causes of death were the following: progressive heart failure, 24; sudden death, 23; stroke, 3; pulmonary embolism, 2; noncardiac death, 4; unknown causes, 29. The median period from the onset of first symptoms until definite diagnosis was two months in patients with stable conditions, three months in those with normalization of LVEF and twenty-four months in those who died, respectively (P < 0.01). At the time of diagnosis, patients with stable outcome had a mean LVEF (LVEF 1) of 37%, those who returned to normal had 40% (ns). Patients who died had a mean LVEF 1 of 32% and therefore differed significantly from both groups of survivors (P < 0.001). Left ventricular end-diastolic pressure (LVEDP) at the time of diagnosis was highest in patients who died (22 mmHg) and therefore differed significantly from both groups of survivors (normalization: 16 mmHg, stable patients: 18 mmHg, P < 0.001).

CONCLUSIONS

According to their results, time until diagnosis, LVEF, and LVEDP are prognostic indicators. No difference was noted between the groups concerning etiology, medical treatment, or functional classification according to the New York Heart Association.

Can the electrophysiologic study predict treatment outcome in patients with sustained ventricular tachyarrhythmias unrelated to coronary artery disease?

Sustained ventricular tachyarrhythmias unrelated to coronary artery disease are uncommon. Currently there are no clear guidelines to aid selection of the most appropriate treatment strategy. Therefore, factors potentially predictive of arrhythmia recurrence and death and the ability of the electrophysiologic study to predict treatment outcome in patients with spontaneous sustained ventricular tachyarrhythmias unrelated to coronary artery disease were examined in 41 medically treated patients followed for a median of 25 (range 1-76) months. Examined factors were: syncope associated with the spontaneous arrhythmia, the morphology and cycle length of the presenting arrhythmia, underlying ventricular function, cardiac pathology, and the results of drug assessment at electrophysiologic study. Random variability in the ease of arrhythmia induction at electrophysiologic study was measured for the group as a whole and was allowed for in prediction of an effective drug response. The 95% confidence intervals for variability in the ease of repeat arrhythmia induction at the same study were < or = 1 extrastimulus and for variability in the ease of repeat arrhythmia inductions at different studies were < or = 2 extrastimuli. Poisson regression models were used for data analysis. Arrhythmia recurrence was most likely in: (1) patients on treatment not predicted to be anti-arrhythmic at electrophysiologic study; (2) patients whose treatment was not assessable at electrophysiologic study because the arrhythmia was not reliably inducible; (3) patients with impaired ventricular function; and (4) re-entered patients whose arrhythmia had recurred on previously allocated therapy. The risk of arrhythmia recurrence decreased with time from hospital assessment. All five deaths occurred in patients with impaired ventricular function.

CONCLUSIONS

drug efficacy should be tested at electrophysiologic study in patients with reproducibly inducible clinical arrhythmias. Treatment not proven to be anti-arrhythmic at electrophysiologic study is usually ineffective. Patients with ventricular dysfunction are at highest risk of death from arrhythmia recurrence and should be considered for an implantable defibrillator, arrhythmia surgery, or heart transplantation if drug treatment is not predicted to be effective or is not assessable at electrophysiologic study.

Prognosis in congestive heart failure

Prognostic variables such as the ejection fraction and peak oxygen consumption can be used to place patients with heart failure in risk strata. Some vasodilators have been shown to improve survival at all stages of heart failure with the probability of benefit increasing as the prognosis worsens. Quantitative estimates of survival among groups defined by prognostic variables and treatments should be used to make more informed benefit-to-risk assessments.

Prognostic implications of clinical, electrocardiographic and hemodynamic findings in chronic Chagas' disease

To evaluate the prognostic importance of 19 clinical, electrocardiographic and hemodynamic variables, 556 chronic chagasic patients were submitted to an extensive protocol, including left cineventriculogram and Holter monitoring, and followed for up to 15 years. The protagonist role of the magnitude of the myocardial compromise in the evolution of chagasic patients is underscored by our results, which indicated the independent prognostic value of an ejection fraction below 0.30 (P < 0.001), a heart rate higher than 89 beats/min (P < 0.01), grade IV functional capacity (P < 0.05), end systolic stress > 120 g/cm2 (P < 0.05), and end diastolic volume index > 200 ml/m2 (P < 0.05). When only patients with an ejection fraction over 0.29 were considered, variables with independent prognostic value were: the cardio-thoracic ratio (P < 0.01), functional capacity (P < 0.05) and heart rate (P < 0.05). Survival analysis demonstrated that the presence of complex (Lown III, IV) ventricular arrhythmias increased mortality significantly (P < 0.01) only in patients with an ejection fraction over 0.29. Therefore, preservation of myocardial function is the capital measure in the treatment of chronic chagasic patients.

Comparison of clinical findings in idiopathic dilated cardiomyopathy in women versus men. The Italian Multicenter Cardiomyopathy Study Group (SPIC)

Clinical and laboratory findings were compared in 65 women and 238 men with invasively documented idiopathic dilated cardiomyopathy. Women had more severe symptoms (New York Heart Association class > or = III in 48 vs 39%; p < 0.05), presented more frequently with heart failure signs (63 vs 41%; p < 0.01), and had a higher cardiothoracic ratio (0.56 +/- 0.06 vs 0.53 +/- 0.06; p < 0.05) and higher frequency of left bundle branch block (41 vs 29%; p < 0.05). Echocardiographic measurements in women showed significantly greater left ventricular (LV) end-diastolic (42 +/- 7 vs 39 +/- 6 mm/m2; p < 0.0001) and end-systolic (36 +/- 7 vs 33 +/- 6 mm/m2; p < 0.001) diameters, and mean myocardial thickness (11 +/- 2 vs 10 +/- 2 mm; p < 0.05). Exercise duration was shorter in women than in men (7 +/- 3 vs 10 +/- 4 minutes; p < 0.001). After 18 +/- 16 months, 9 women and 27 men died, and 7 and 17, respectively, received transplants. Transplant-free survival was not significantly different according to gender. By Cox multivariate analysis, LV ejection fraction was a significant independent predictor of cardiac death or heart transplantation in both sexes (p < 0.05 in men, and p < 0.005 in women), together with left atrial diameter index (p < 0.01) in women, and mean pulmonary artery pressure (p < 0.001) in men. In conclusion, women with idiopathic dilated cardiomyopathy present a more advanced phase of the disease with greater LV dilation, but do not have a different prognosis.

The rationale for prophylactic implantation of a defibrillator in "high risk" patients

The increasing technological developments have made it possible to have implantable defibrillators with a wide range of diagnostic and therapeutic capabilities, which can be implanted without the need for a thoracotomy. It is not surprising, therefore, that the indications for implantation of a defibrillator have rapidly evolved. Defining populations of patients in whom a true "prophylactic" implantation (before the first episode of ventricular tachycardia or ventricular fibrillation) may be justified is still difficult. However, the time has certainly come to provide a cardioverter defibrillator to all patients who have suffered from one episode of ventricular tachycardia or ventricular fibrillation and who are at real risk of sudden arrhythmic death. Identification of these patients is relatively easy. It can be done using simple variables from the clinical history. Results from an ongoing multicenter trial testing the hypothesis that clinical variables can indeed be used to stratify the risk of sudden death and to select candidates for a defibrillator have proven the validity of this approach. There is no medical justification to withhold implantation of a cardioverter defibrillator in the truly "high risk" patient. One has to realize, however, that the concept of "high risk" is relative, and that the indications for the implantable defibrillator will continue to broaden.