Effects of limiting fluid intake on clinical and laboratory outcomes in patients with heart failure. Results of a meta-analysis of randomized controlled trials

BACKGROUND

The guidelines of the Scientific Societies of Cardiology recommend limiting fluid intake as a nonpharmacological measure for the management of chronic heart failure (HF). However, many patients with HF may suffer from severe thirst. A meta-analysis was performed to evaluate the effect of limiting fluid consumption based on various clinical and laboratory outcomes in patients with chronic HF.

METHODS

Only randomized controlled trials comparing liberal and restricted fluid oral intake in patients with HF were included. Primary outcomes were HF hospitalizations and all-cause mortality. Secondary outcomes were the sensation of thirst, the duration of therapy with intravenous diuretics, and the serum levels of creatinine, sodium, and B-type natriuretic peptide (BNP).

RESULTS

Six studies met the inclusion criteria. Significant heterogeneity was detected for the majority of outcomes. In 5 studies, patients with restricted fluid intake compared to patients with free consumption of beverages had similar rehospitalization and mortality rates. There were no differences regarding patients' sense of thirst (4 studies), duration of intravenous diuretic treatment (2 studies), serum creatinine levels (5 studies), and serum sodium levels (5 studies). Serum BNP levels were significantly higher in the group with free fluid intake (4 studies).

CONCLUSION

In patients with HF, liberal fluid consumption does not seem to exert an unfavorable impact on HF rehospitalizations or all-cause mortality. Further randomized controlled trials are warranted to definitively confirm the present findings.

Cardiovascular risk associated with celecoxib or etoricoxib: a meta-analysis of randomized controlled trials which adopted comparison with placebo or naproxen

AIM

The present meta-analysis attempted to assess whether an unfavourable cardiovascular risk profile could be identified in the case of two COX2 selective inhibitors (COXIBs), namely celecoxib and etoricoxib. Based on the data from the literature, our meta-analysis aimed to assess the probability of major cardiovascular events reported with the use of celecoxib or etoricoxib and compare this with the results seen in patients assigned to the placebo group. Furthermore, the risk of cardiovascular events found by using celecoxib or etoricoxib was also compared with that associated with the use of naproxen, a nonselective non-steroidal anti-inflammatory drug (NSAID) chosen as our reference drug.

METHODS

The studies had to be randomized controlled trials with at least 4-week duration. Studies were included if they compared celecoxib or etoricoxib against placebo or naproxen. Moreover, the selected studies had to have determined the risk, odds or incidence of myocardial infarction, stroke or cardiovascular death. For the comparisons versus placebo, the endpoints of interest were "serious vascular events", "non-fatal myocardial infarction", "non-fatal stroke" and "death from cardiovascular causes", whereas "myocardial infarction" and "stroke" were the endpoints of interest concerning the comparison versus naproxen.

RESULTS

From the evaluation of 41 studies comparing celecoxib with placebo, we found a significantly higher incidence of serious vascular events in the celecoxib group compared to controls treated with placebo (rate ratio 1.598, 95% CI: 1.048 to 2.438; P=0.029). Furthermore, in patients allocated to treatment with celecoxib, we found an incidence rate of non-fatal acute myocardial infarction that was three times higher compared with the placebo group (rate ratio 3.074, 95% CI: 1.375-6.873, P=0.006). In contrast, we did not find any significant difference with regard to the incidence of nonfatal stroke and that of death from cardiovascular causes by comparing celecoxib and placebo. In addition, by examining cardiovascular outcomes that emerged from the 17 trials which compared etoricoxib with placebo, it was not possible to demonstrate statistically significant differences in incidence for each of the explored endpoints. With regard to the comparison of each coxib with the non-selective COX2 inhibitor naproxen, we did not find any significant difference for either the odds of myocardial infarction or that of stroke.

CONCLUSION

On the basis of our meta-analysis, we can state that symptomatic benefits induced by the prolonged administration of celecoxib may be partially invalidated by a concomitant increase in vascular risk, particularly the increased risk of myocardial infarction found in celecoxib-treated patients, compared to controls taking placebo. In contrast, treatment with etoricoxib proved not to result in an increased risk of serious vascular events when compared with both the placebo and naproxen. Our meta-analysis also denotes that the alternative to COXIBs, represented by naproxen, does not show significant benefit in terms of reduced cardiovascular risk. Therefore, considering that the increase in incidence rate of cardiovascular events associated with treatment with celecoxib is small in absolute terms, it is reasonable to state that celecoxib is still a drug whose benefits outweigh the potential adverse effects on the cardiovascular system.

In right or biventricular chronic heart failure addition of thiazides to loop diuretics to achieve a sequential blockade of the nephron is associated with increased risk of dilutional hyponatremia: results of a case-control study

AIM

Chronic hyponatremia is frequently found in some syndromes characterized by widespread edema coupled to impairment in arterial effective circulating volume, such as congestive chronic heart failure (CHF). In this setting, it is unclear whether the hyponatremia itself makes this condition worse or whether it represents a simply marker of decompensation. The factors responsible for development of hyponatremia in CHF have not exhaustively been elucidated yet. The aim of this paper was to ascertain whether some laboratory, clinical and therapeutical factors are able to predict occurrence of hyponatremia in CHF patients.

METHODS

A case-control study was carried out by recruiting 57 CHF patients, whose 19 characterized by hyponatremia (serum Na+<135 mEq/L) and 38 controls, matched for age, sex, etiology of CHF, time elapsed since beginning of both symptoms and diuretic therapy. Eligibility criteria included right or biventricular heart failure in NYHA class III, absence of hyponatremia at the first visit and therapy at enrollment with oral dose not less than 175 mg per week of furosemide or equivalent weekly dose of torsemide. Exclusion criteria were electrostimulation therapies (pace-maker or cardiac resynchronization therapy), documented episodes- one or more- of infective gastroenteritis or diarrhea and use of any drug influencing neuroendocrine mechanisms of arginin-vasopressin (AVP) secretion, such as opiates, tetracyclines, phenothiazines, lithium, serotonin selective reuptake inhibitors (SSRIs) etc.

RESULTS

At univariate analysis, intensive intravenous (iv) therapy with furosemide (one or more courses), ascites, mixed regimen with thiazide diuretic plus furosemide, high (>3 ng/mL/h) plasma renin activity, serum creatinine ≥2,2 mg/dl and oligoanuria were shown to be associated with hyponatremia. At multivariate analysis a role of predictor of hyponatremia was maintained by combined therapy with thiazide diuretic plus furosemide (OR=35.68 95%CI: 2.83-449.37 P=0.0057) as well as by intensive iv furosemide therapy (OR=12.44 95%CI: 1.207-128.27 P=0.0342).

CONCLUSION

Inhibition of free water clearance by thiazides may account for association found between their use and hyponatremia development in congestive CHF setting. Even though loop diuretics are known to promote free water excretion, in our experience hyponatremia might have been favored by iv furosemide high doses, because drop in effective circulating volume and further impairment in arterial underfilling due to overzealous iv loop diuretic administration are able to foster AVP non osmotic release, thereby leading to hemodilution hyponatremia.

In chronic heart failure with marked fluid retention, the i.v. high doses of loop diuretic are a predictor of aggravated renal dysfunction, especially in the set of heart failure with normal or only mildly impaired left ventricular systolic function

AIM

In the presence of resistance to oral diuretics in chronic heart failure (CHF) patients with extreme hydrosaline retention, among the proposed therapeutic options the administration of high doses of loop diuretics - either intravenous (i.v.) boluses or i.v. continuous infusion - should first of all be considered. Nevertheless, the use of this therapy may lead to the risk of further aggravation of frequently coexisting renal dysfunction, especially when loop diuretics such as furosemide (FUR), torasemide etc. are administered at excessive doses leading to hypotension, hypoperfusion and/or relative dehydration in patients with decompensated CHF who could have benefit from intensive unloading therapy. The aim of this study was to identify the clinical and hematochemical markers which are able to predict a possible decline or rapid deterioration of renal function implying a rise in serum creatinine (Cr) >25% of its basal value, i.e. the so-called aggravated renal dysfunction (ARD), typically occurring during intensive unloading therapy with i.v. FUR or other loop diuretics, administered to CHF pts with extreme fluid retention.

METHODS

The protocol of our case-control observational study established to enroll every CHF patient who was demonstrated to develop a rise in Cr suggestive of ARD at the end of i.v. diuretic therapy (VI-VIII day). For each case enrolled, 3 patients at least were selected as controls, matched for age, sex and time elapsed from the beginning of the signs and symptoms of CHF. For the prediction of the dependent variable, represented by ARD diuretic infusion-related, the following independent variables were considered: creatinine clearance (Cr clear) <60 mL/min, Cr clear expressed as a continuous variable (Cr clear continuous), daily dose of i.v. furosemide ≥ 125 mg, left ventricular ejection fraction (LVEF), CHF with normal (≥ 50%) LVEF (HFNEF), urinary sodium concentration (U Na+) ≥ 40 mEq/L, U Na+expressed as a continuous variable (U Na+ continuous), sodium fractional excretion (FE Na+) >2%, urine/plasma concentration ratios for creatinine (U/P cr) <10, for urea (U/P urea) <5 and for osmolality (U/P osmolal) <1.1, mean duration of the symptoms of CHF, history of pre-existing parenchymal renal disease . The values of U Na+, FE Na+, U/P Cr, U/P urea and U/P osmolal were measured after discontinuance of diuretic oral therapy for four days, before the onset of intensive i.v. diuretic administration, so as to identify the patients with pathological values of tubular renal function indexes, known to be not interpretable in the presence of diuretics, suggestive of possible preexisting anatomic renal damage (acute tubular necrosis prior to onset of iv diuretic therapy).

RESULTS

Nineteen 19 CHF patients with ARD and 60 controls were enrolled. At univariable analysis, Cr clear <60 mL/min, Cr clear continuous, daily dose of iv furosemide ≥ 125 mg, LVEF, HFNEF, FE Na+>2%, Na+≥ 40 mEq/L and U Na+ continuous were shown to be associated with ARD. At multivariate analysis, the role of prognostic indicator of ARD was maintained by daily dose only of iv FUR ≥125 mg (OR: 7.2088 95% CI: 1.3096-39.6802 P=0.0232). By using the 2x2 contingency tables, a qualitative interaction was identified by crossing ARD ‑ outcome variable - against dose of iv FUR ≥ 125 mg/day - exposure variable - and by subsequently stratifying by the HFNEF. Actually, a significant association with ARD was not present in any CHF patient with dilated left ventricle treated with high dosage of iv FUR, whereas a highly significant association with ARD was observed in HFNEF patients (OR: 72 95% CI: 6.601-785.2694 P=0.00001) who had experienced the same high iv fur dose.

CONCLUSION

In CHF patients with widespread edema refractory to oral diuretic, ARD can be propitiated by high dosages of i.v. FUR, when not associated with other treatments to preserve the effective circulating volume and renal flow. The HFNEF patients appear to be more prone to ARD related to i.v. high dosages of FUR, perhaps because their hemodynamics is more seriously harmed by the drop, FUR-related, in venous return and cardiac preload, as compared to CHF patients with reduced (45-30%) LVEF.

[Renoprotective effect of small volumes of hypertonic saline solution in chronic heart failure patients with marked fluid retention: results of a case-control study]

During intensive therapy of chronic heart failure (CHF) patients with marked fluid retention using high doses of i.v. furosemide the additional effect of agents which might exert osmotic attraction of interstitial fluids has been proposed. They are thought to impede the impairment of renal blood supply and glomerular filtration rate, which may be caused by a combined action of cardiac preload acute reduction, hypotension and neurohormonal activation.We therefore assessed in CHF patients with NYHA class III and BNP values from 900 to 1500 pg/ml, who were treated with i.v. furosemide, the predictors of iatrogenic short term creatinine impairment by means of a case-control observational study from two centers. Patients with CHF had been treated for 6-8 days with intravenous loop diuretics alone or with an additional i.v. administration of other agents (plasma expanders, albumin, mannitol, inotropic support etc.). A rise in serum creatinine ≥ 25% of the basal value was considered as renal impairment.A total of 15 cases and 38 controls were enrolled. At univariate analysis, serum creatinine basal value ≥ 2.2 mg/dl, absence of hypertonic saline solution (HSS) in the therapeutic protocol, hyposodic diet and refractory oligoanuria were associated with an increased risk of worsening renal function precipitated by i.v. diuretic therapy. At multivariate analysis as a predictor of loop diuretic-related renal function impairment, we found a serum creatinine ≥ 2.2 mg/dl at baseline (OR: 63.33, 95% CI: 3.68-1088.73, p=0.0043) and the absence of HSS in the therapeutic regimen (OR: 25.0461, 95% CI: 2.07-302.53, p=0.0113). Moreover, in multivariate analysis ascites had some predictive value of renal deterioration (OR: 13.28, 95% CI: 1.0055-175.41, p=0,0495).

The risk of worsening CHF is positively related to unitary increase in mitral regurgitation size: a case-cohort study derived from a II NYHA class CHF patient population

AIM

The passage from II to III New York Heart Association (NYHA) class is indicative of cardiopulmonary impairment and unfavourable prognosis. Among chronic heart failure(CHF) II NYHA class patients, the topic has been debated what criteria have be assumed for identifying the patients prone to accelerated progression towards III NYHA class.

METHODS

A case cohort study, including a number of CHF II NYHA class patients, was carried out, to evaluate the role as predictor of CHF worsening of some ultrasonographic parameters, listed as follows: left ventricular ejection fraction, as continuous and as a dichotomous variable, i.e. subdivided as follows: 1) LVEF larger than 40% and 2) LVEF ranged from 30% to 40%; mitral regurgitation (MR), as continuous and as a dichotomic variable (i.e. moderate-to-severe MR, defined by transmitralic jet planimetric area estimated as larger than 20% of left atrium area), restrictive LV filling pattern and pulmonary systolic arterial pressure >40 mmHg. The pts were subdivided in 3 categories, as follows:1) diastolic CHF, i.e. heart failure with normal or only mildly impaired left ventricular ejection fraction - 20 patients; 2) systolic CHF, i.e. heart failure with reduced left ventricular ejection fraction - 19 patients; and 3) CHF due to "organic" mitral insufficiency-19 patients. All patients were treated with pharmacologic therapy, according to their respective clinical features and typology of basal heart disease. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) for the composite endpoint death and hospitalization due to worsening CHF were investigated, concerning each of the above-mentioned criteria. Moreover, the odds ratios (OR) were calculated, by not conditional logistic regression analysis, to achieve information about risk of death and/or worsening CHF, as well as the respective profiles of risk, assessed by relative risk (RR).

RESULTS

From 173 followed-up patients, 58 patients,70+/-12 aged, whose 15 cases (transition to III NYHA class) and 43 controls, were included in retrospective analysis. Notewhorty, moderate-to-severe MR only seemed to play a role as reliable predictor of worsening CHF(sensitivity: 93.3%; specificity: 69.7%; PPV: 51.8%; NPV: 96.7%; RR:15.93; OR: 32.3), as its sensitivity and PPV, particularly, were shown to exceed far and away the values of sensitivity and PPV associated to each of other echographic and/or clinical variables. Nevertheless, at multivariate analysis,MR expressed as continuous variable only, but not as "categorical" variable-was demonstrated to independently predict the transition from II to III NYHA class, over two years clinical follow up.

CONCLUSION

The present data seem to support the view that the larger regurgitant jet of mitral insufficiency, the higher the risk of worsening CHF during a two years follow up. Likewise, it is plausible the moderate-severe MR represents a predictor of increased risk of transition to III NYHA class among the CHF II NYHA class patients. In addition, this study seems to indicate that a surgical therapy (prosthetic replacement or mitral valvuloplasty)should always be planned in the case of II NYHA class CHF patient who has been recognized affected by moderate-to-severe MR, since the chances of successful pharmacological prevention of clinical impairment in this setting turned out to be very slight.

Correlation between late potentials duration and QTc dispersion: Is there a causal relationship?

QTc interval dispersion (QTcd) analysis (difference between maximum and minimum QTc calculated from at least five of the standard 12 ECG leads) and signal-averaged electrocardiograms were performed on 23 patients referred to our coronary care unit because of acute myocardial infarction. Late potentials were considered positive if all three of the following criteria were satisfied: (1) total QRS duration (QRSd) > 114 ms; (2) duration of QRS under 40 muV (LAS 40) > 38 ms; (3) root mean square voltage of the last 40 ms of QRS (RMS 40) < 25 muV. Patients were divided into two groups according to the presence (group A, 9 patients) or absence of late potentials (group B, 14 patients). Group A patients showed a significantly higher QTcd (0.0652 +/- 0.0177 s vs. 0.0448 +/- 0.0201 s; P = 0.021) and a significantly longer mean QTcm (0.43117 +/- 0.01817 s vs. 0.40472 +/- 0.03013 s; P = 0.028) than group B patients. Among the three different parameters used to define the presence of late potentials, QTcd was significantly related to LAS 40 (r = 0.418, P = 0.047) and mean QT cm to QRSd (r = 0.497; P = 0.016). We also found a significant correlation between QTcd and mean QTcm (r = 0.426; P = 0.043). In conclusion, our data suggest that (1) the presence of late potentials is associated with a greater dishomogeneity of ventricular recovery time; (2) the longer the duration of late potentials, expressed by LAS 40, the greater the QTcd, suggesting that the dispersion of repolarization could be attributed to slowly conducting areas from which late potentials arise; (3) mean QTcm is not useful to identify these areas because it is more affected by total rather than by terminal QRS duration; (4) regional discrepancies of ventricular recovery time are connected with general repolarization duration.

[Myocardial infarct without Q wave in the elderly: diagnostic evaluation using vectorcardiography]

The diagnosis of previous non-Q wave myocardial infarction by standard electrocardiographic investigation is uncertain, particularly in elderly patients because of concomitant disease. We have studied 31 elderly patients (aged 63-72 years) with a diagnosis of non-Q wave myocardial infarction between 1-6 months after this acute event. The patients underwent clinical-anamnestic examination, standard electrocardiography, vectorcardiography according to the Frank system and M-mode and 2-D echo-cardiography with continuous and pulsated Doppler. The ECG showed ST-T anomalies in 12 patients (38.7%) whereas the VCG showed anomalies of QRS-loop normal convexity in 27 patients (87%) and 16 of these (51.6%) showed bites criteria (duration > or = 10 msec, voltage > or = 0.1 mV, present at least on two planes). By echocardiography, regional hypo-akinesia was observed in 19 patients (61.3%). Although bites are not only present in myocardial infarction, they indicate an interruption of myocardial gradual electric activation, compatible with fibrous areas, and should be evaluated as a part of the clinical-anamnestic, laboratory and instrumental data.

[Infectious endocarditis in dentistry practice: recent controversies and modes of the use of antibiotic prophylaxis]

A survey by questionnaire to assess the daily practice of the antibiotic prophylaxis of infective endocarditis by physicians attending post-graduate schools of the Institutes of Oral Surgery and Stomatology (Group A n = 83) and Cardiology (Group B n = 46) of the Second University of Naples has been conducted. They were asked about dental procedure and cardiopathies that require prophylaxis for infective endocarditis, the relationship between infective endocarditis and rheumatic disease and the provision of antibiotic. Extraction of tooth and dental and oral surgery have been reported as the most risky procedures. Moreover provision of antibiotic prophylaxis was suggested to patients not at risk (pacemaker or coronary artery bypass), and was not suggested in high risk conditions (mitral valve prolapse with regurgitation and hypertrophic cardiomyopathy). Most of the 50-60% practitioners usually start the prophylaxis 24-48 hours before the procedure and prolong it for 48-72 hours. These results underline the need for improvement of the knowledge for the antibiotic prophylaxis of infective endocarditis.