Effects of loop diuretics on myocardial fibrosis and collagen type I turnover in chronic heart failure

Impact of treatment on myocardial lysyl oxidase expression and collagen cross-linking in patients with heart failure

The aim of this study was to investigate whether torasemide modifies collagen cross-linking in the failing human heart. We analyzed the degree of cross-linking and the expression of the enzyme lysyl oxidase, which regulates cross-linking, in the myocardium of patients with chronic heart failure at baseline and after 8 months of treatment with either torasemide or furosemide in addition to their standard heart failure therapy. Whereas lysyl oxidase protein expression was very scarce in normal hearts, it was highly expressed in failing hearts. Cross-linking was increased (P<0.001) in heart failure patients compared with normal hearts. These 2 parameters decreased (P=0.021 and P=0.034) in torasemide-treated patients and remained unchanged in furosemide-treated patients. In addition, more (P=0.009) patients showed normalization of left ventricular chamber stiffness in the torasemide subgroup than in the furosemide subgroup after treatment. Lysyl oxidase expression correlated with cross-linking (r=0.661; P<0.001), and cross-linking correlated with left ventricular chamber stiffness (r=0.452; P=0.002) in all patients. These findings show for the first time that lysyl oxidase overexpression is associated with enhanced collagen cross-linking in the failing human heart. In addition, we report that the ability of torasemide to correct both lysyl oxidase overexpression and enhanced collagen cross-linking results in normalization of left ventricular chamber stiffness in patients with heart failure. Lysyl oxidase may thus represent a target for reduction of stiff collagen and improvement of left ventricular mechanical properties in heart failure patients.

Inpatient management of patients with volume overload and high filling pressures

The majority of patients with acute decompensated heart failure are admitted with symptoms of congestion. The classic symptoms of "congestive" heart failure reflect fluid overload, that is, orthopnea, paroxysmal nocturnal dyspnea, and peripheral edema; these symptoms can be so dramatic that it is not surprising that patients seek hospitalization. Activation of the renin angiotensin system coupled with sympathetic hyperactivity results in marked sodium retention and high filling pressures that ultimately bring about these congestive symptoms. The treatment goal of patients hospitalized with volume overload and high filling pressures is to improve symptoms by normalizing the filling pressure and volume status without worsening renal function. The current use of diuretics, vasodilators, and ultrafiltration, as well as potential future use of investigational agents such as oral vasopressin antagonists and adenosine A1-receptor antagonists, is surrounded by the important issues of when to stop intravenous therapy in hospitalized patients and the exact mechanism by which the filling pressures are normalized. New data from evidence-based clinical trials and optimal strategies for monitoring fluid overload will help define this issue and ultimately reduce mortality in these patients.

Diagnosis and treatment of myocardial fibrosis in hypertensive heart disease

Although hypertensive heart disease (HHD) is clinically characterized by development of left ventricular hypertrophy in the absence of a cause other than arterial hypertension, changes in the composition of myocardial tissue also develop in arterial hypertension, leading to structural remodeling of the myocardium (eg, fibrosis). Myocardial fibrosis is the major determinant of diastolic dysfunction/failure in patients with HHD. Recent available data on the determination of serum concentrations of collagen-derived serum peptides, as well as quantitative analysis of echoreflectivity to address the presence of fibrosis in the myocardium of hypertensive patients, are promising. In addition, preliminary data suggest that the goal of reducing myocardial fibrosis is achievable using specific pharmacological agents in patients with HHD.

Treatment of hypertension in heart failure with preserved ejection fraction: role of the kidney

Heart failure can present clinically as primarily diastolic or systolic dysfunction or both. There is an increasing awareness that heart failure can occur in the presence of a normal left ventricular ejection fraction. Heart failure with normal left ventricular ejection fraction is frequently referred to as diastolic heart failure because of the presence of diastolic left ventricular dysfunction evident from impaired left ventricular relaxation. This article focuses on the treatment of hypertension and the role the kidney plays in selecting appropriate agents.

Serum carboxy-terminal telopeptide of type I collagen (ICTP) predicts cardiac events in chronic heart failure patients with preserved left ventricular systolic function

BACKGROUND

Clinical markers to predict adverse outcome have not yet been established for patients with preserved left ventricular (LV) systolic function. The present study was designed to examine whether carboxy-terminal telopeptide of type I collagen (ICTP), a marker of collagen degradation, is useful for determining the prognosis of such patients.

METHODS AND RESULTS

Serum levels of ICTP were measured at admission in 156 consecutive patients hospitalized for chronic heart failure (CHF). Patients were divided into 2 groups based on the LV ejection fraction (LVEF): reduced LV systolic function group (LVEF <50%, n=92) and preserved LV systolic function group (LVEF > or =50%, n=64). In preserved LV systolic function group, cardiac event-free rates were significantly lower in high ICTP group than in low ICTP group (p<0.001). The area under the receiver operating characteristic curve of ICTP in the preserved LV systolic function group was markedly larger than that in the reduced LV systolic function group. Cox multivariate analysis also revealed that ICTP was an independent predictor of cardiac events in the preserved LV systolic function group.

CONCLUSION

Serum ICTP level is highly reliable for risk stratifying CHF patients with preserved LV systolic function.

A propensity-matched study of the effects of chronic diuretic therapy on mortality and hospitalization in older adults with heart failure

BACKGROUND

Non-potassium-sparing diuretics may increase mortality and hospitalizations in heart failure patients. Most heart failure patients are older adults, yet the effect of diuretics on cause-specific mortality and hospitalizations in older adults with heart failure is unknown. The objective of this propensity-matched study was to determine the effect of diuretics on mortality and hospitalizations in heart failure patients >or=65 years.

METHODS

Of the 7788 Digitalis Investigation Group participants, 4036 were >or=65 years and 3271 (81%) were receiving diuretics. Propensity scores for diuretic use for each of the 4036 patients were calculated using a non-parsimonious multivariable logistic regression model incorporating all measured baseline covariates, and were used to match 651 (85%) patients not receiving diuretics with 651 patients receiving diuretics. Effects of diuretics on mortality and hospitalization at 37 months of median follow-up were assessed using matched Cox regression models.

RESULTS

All-cause mortality occurred in 173 patients not receiving diuretics and 208 patients receiving diuretics respectively during 2056 and 1943 person-years of follow-up (hazard ratio {HR}=1.36; 95% confidence interval {CI}=1.08-1.71; p=0.009). All-cause hospitalizations occurred in 413 patients not receiving and 438 patients receiving diuretics respectively during 1255 and 1144 person-years of follow-up (HR=1.18; 95% CI=0.99-1.39; p=0.063). Diuretic use was associated with significant increased risk of cardiovascular mortality (HR=1.50; 95% CI=1.15-1.96; p=0.003).and heart failure hospitalization (HR=1.48; 95% CI=1.13-1.94; p=0.005).

CONCLUSIONS

Chronic diuretic use was associated with significant increased mortality and hospitalization in ambulatory older adults with heart failure receiving angiotensin converting enzyme inhibitor and diuretics.

Identification of a potential cardiac antifibrotic mechanism of torasemide in patients with chronic heart failure

OBJECTIVES

This study sought to investigate whether torasemide inhibits the enzyme involved in the myocardial extracellular generation of collagen type I molecules (i.e., procollagen type I carboxy-terminal proteinase [PCP]).

BACKGROUND

Torasemide has been reported to reduce myocardial fibrosis in patients with chronic heart failure (HF).

METHODS

Chronic HF patients received either 10 to 20 mg/day oral torasemide (n = 11) or 20 to 40 mg/day oral furosemide (n = 11) in addition to their standard HF therapy. At baseline and after 8 months from randomization, right septal endomyocardial biopsies were obtained to analyze the expression of PCP by Western blot and the deposition of collagen fibers (collagen volume fraction [CVF]) with an automated image analysis system. The carboxy-terminal propeptide of procollagen type I (PICP) released as a result of the action of PCP on procollagen type I was measured in serum by radioimmunoassay.

RESULTS

The ratio of PCP active form to PCP zymogen, an index of PCP activation, decreased (p < 0.05) in torasemide-treated patients and remained unchanged in furosemide-treated patients. A reduction (p < 0.01) in both CVF and PICP was observed in torasemide-treated but not in furosemide-treated patients. Changes in PCP activation were positively correlated (p < 0.001) with changes in CVF and changes in PICP in patients receiving torasemide.

CONCLUSIONS

These findings suggest the hypothesis that the ability of torasemide to reduce myocardial fibrosis in chronic HF patients is related to a decreased PCP activation. Further studies are required to ascertain whether PCP may represent a new target for antifibrotic strategies in chronic HF.

Optimal use of diuretics in patients with heart failure

Currently, the use of diuretics in heart failure (HF) remains more of an art than a science. Diuretics are the principle means for relieving congestion in patients with decompensated HF. Unfortunately, they persist as the only major therapy in HF that has not been subjected to a large randomized clinical trial, precisely because no comparable therapy exists that can so easily, efficiently, and inexpensively treat fluid overload. Nonetheless, diuretics have many potential drawbacks, including electrolyte abnormalities, neurohormonal activation, hypovolemia, renal dysfunction, and direct myocardial effects. Until definitive answers about mortality are settled, the lowest dose of a diuretic that can produce euvolemia should be employed and these agents should be discontinued when possible. Many outpatients with HF can be managed quite well without diuretics once adequate neurohormonal blockade with angiotensin-converting enzyme inhibitors and beta blockers has been achieved.

Propeptide of procollagen type I (PIP) and outcomes in decompensated heart failure

BACKGROUND

Changes in extracellular matrix are recognized as a contributing factor in the cardiac remodeling process. Several studies have addressed the value of turnover markers of collagen as predictors of death or new heart failure episodes. The aim of the present study was to evaluate the relationship between peripheral serum concentration of propeptide of procollagen type I (PIP) and outcomes in patients with decompensated heart failure.

METHODS

A total of 111 patients admitted to our Unit between September 2000 and May 2003 for decompensated heart failure were analyzed. Death from any cause or due to heart failure and readmission were considered primary endpoints.

RESULTS

The mean PIP concentration was 80.84+/-36.40 ng/mL. The PIP serum level was significantly higher among those patients who suffered some endpoint during follow-up (88.12+/-37.31 ng/mL vs 73.13+/-34.06 ng/mL; p=0.029). Twenty-five (22.52%) of the 111 patients died during the 21 months of follow-up, and 54 (48.6%) were readmitted with new bouts of heart failure. Using Cox proportional hazards regression analyses, serum PIP levels, systolic dysfunction, and diabetes mellitus were identified as independent predictors of death. Serum PIP levels, age, and sex were independent predictors of new heart failure episodes and readmission.

CONCLUSION

A single serum measurement of PIP seems to have prognostic value in patients with decompensated heart failure. Accordingly, patients with higher values of PIP at decompensation are at a higher risk of death or readmission during follow-up.

[Altered fibrillar collagen metabolism in hypertensive heart failure. Current understanding and future prospects]

Arterial hypertension induces numerous alterations in the composition of cardiac tissue, which, in turn, result in structural remodeling of the myocardium. This remodeling is due to a range of pathologic mechanisms associated with mechanical, neurohormonal and cytokine processes that affect both cardiomyocyte and non-cardiomyocyte compartments of the myocardium. One of these processes involves disruption of the equilibrium between the synthesis and degradation of type-I and type-III collagen molecules. The result is excess accumulation of type-I and type-III collagen fibers in interstitial and perivascular spaces in the myocardium. The clinical significance of myocardial fibrosis lies in its contribution to the development of cardiac complications in hypertensive patients. This brief review focuses on the mechanisms of myocardial fibrosis and their clinical consequences. In addition, the techniques used for diagnosing myocardial fibrosis and the main therapeutic strategies for reducing fibrosis are also discussed.

Diastolic heart failure: evidence of increased myocardial collagen turnover linked to diastolic dysfunction

BACKGROUND

The pathophysiology of diastolic heart failure (DHF) is poorly understood. One potential explanation is an active fibrotic process that produces increased ventricular stiffness, which compromises filling. The present study investigates collagen metabolism in hypertensive patients in different phases of diastolic function with and without proven DHF.

METHODS AND RESULTS

We studied 86 hypertensive patients divided into groups according to the presence of DHF (32 with, 54 without) and phase of diastolic function (20 with normal function, 38 with impaired relaxation, 10 with pseudonormalization, and 16 with restrictive-like filling). Serum carboxy-terminal, amino-terminal, and carboxy-terminal telopeptide of procollagen type I, amino-terminal propeptide of procollagen type III, matrix metalloproteinases (MMPs; total MMP-1, active MMP-2, and MMP-9), and tissue inhibitor of MMPs levels were assayed by radioimmunoassay and ELISA. Doppler-echocardiographic assessment of diastolic filling was made with measurements of E/A ratio, E-wave deceleration time, and isovolumic relaxation time. Serum carboxy-terminal telopeptide of procollagen type I, carboxy-terminal telopeptide of procollagen type I, amino-terminal propeptide of procollagen type III, MMP-2, and MMP-9 levels (P<0.001 for all, controlled for age and gender) were greater in patients with DHF than in those without. When we controlled for age and gender, levels of serum carboxy-terminal telopeptide of procollagen type I, tissue inhibitor of MMP-1, amino-terminal propeptide of procollagen type III (all P<0.001), carboxy-terminal telopeptide of procollagen type I (P=0.008), and MMP-2 (P=0.03) were greater in more severe phases of diastolic dysfunction. Within phases of diastolic dysfunction, serum carboxy-terminal telopeptide of procollagen type I, amino-terminal propeptide of procollagen type III, MMP-2, and MMP-9 were elevated in those with DHF compared with those without DHF (all P<0.001).

CONCLUSIONS

These data demonstrate serological evidence of an active fibrotic process in DHF, which is more marked in more severe diastolic dysfunction. This observation may help explain the pathophysiology of DHF and may suggest new avenues for diagnostic and therapeutic intervention.

Systolic and Diastolic Dyssynchrony in Patients With Diastolic Heart Failure and the Effect of Medical Therapy

OBJECTIVES

The purpose of this study was to determine the prevalence of systolic and diastolic dyssynchrony in diastolic heart failure (DHF) patients and identify the effects of medical therapy.

BACKGROUND

The prevalence of systolic and diastolic dyssynchrony in DHF patients is unknown with no data on the effects of medical therapy on dyssynchrony.

METHODS

Patients presenting with DHF (n = 60; 61 +/- 9 years old, 35 women) underwent echocardiographic imaging simultaneous with invasive measurements. An age-matched control group of 35 subjects and 60 patients with systolic heart failure (SHF) were included for comparison. Systolic and diastolic dyssynchrony were assessed by tissue Doppler and defined using mean and SD values in the control group.

RESULTS

Systolic dyssynchrony was present in 20 patients (33%) with DHF and 24 patients (40%) with SHF and was associated in both groups with significantly worse left ventricular (LV) systolic and diastolic properties (p < 0.05 vs. control group and patients without systolic dyssynchrony). Diastolic dyssynchrony was present in 35 patients (58%) with DHF and 36 patients (60%) with SHF and had significant inverse correlations with mean wedge pressure and time constant of LV relaxation. In DHF patients, medical therapy resulted in significant shortening of diastolic time delay (39 +/- 23 ms to 28 +/- 20 ms; p = 0.02) but no significant change in systolic interval (p = 0.15). Shortening of diastolic time delay correlated well with tau shortening after therapy (r = 0.85; p < 0.001).

CONCLUSIONS

Systolic dyssynchrony occurs in 33% of DHF patients, and diastolic dyssynchrony occurs in 58%. Medical therapy results in significant shortening of the diastolic intraventricular time delay which is closely related to improvement in LV relaxation.

Heart failure, chronic diuretic use, and increase in mortality and hospitalization: an observational study using propensity score methods

AIMS

Non-potassium-sparing diuretics are commonly used in heart failure (HF). They activate the neurohormonal system, and are potentially harmful. Yet, the long-term effects of chronic diuretic use in HF are largely unknown. We retrospectively analysed the Digitalis Investigation Group (DIG) data to determine the effects of diuretics on HF outcomes.

METHODS AND RESULTS

Propensity scores for diuretic use were calculated for each of the 7788 DIG participants using a non-parsimonious multivariable logistic regression model, and were used to match 1391 (81%) no-diuretic patients with 1391 diuretic patients. Effects of diuretics on mortality and hospitalization at 40 months of median follow-up were assessed using matched Cox regression models. All-cause mortality was 21% for no-diuretic patients and 29% for diuretic patients [hazard ratio (HR) 1.31; 95% confidence interval (CI) 1.11-1.55; P = 0.002]. HF hospitalizations occurred in 18% of no-diuretic patients and 23% of diuretic patients (HR 1.37; 95% CI 1.13-1.65; P = 0.001).

CONCLUSION

Chronic diuretic use was associated with increased long-term mortality and hospitalizations in a wide spectrum of ambulatory chronic systolic and diastolic HF patients. The findings of the current study challenge the wisdom of routine chronic use of diuretics in HF patients who are asymptomatic or minimally symptomatic without fluid retention, and are on complete neurohormonal blockade. These findings, based on a non-randomized design, need to be further studied in randomized trials.

Effects of torasemide on cardiac sympathetic nerve activity and left ventricular remodelling in patients with congestive heart failure

OBJECTIVE

To determine the effect of torasemide, a loop diuretic with antialdosteronergic properties, compared with furosemide on cardiac sympathetic nerve activity in patients with congestive heart failure (CHF).

METHODS

40 patients with non-ischaemic CHF (left ventricular ejection fraction (LVEF) < 45%) were randomly assigned to torasemide (4-8 mg/day; n = 20) or furosemide (20-40 mg/day; n = 20). All patients were also treated with angiotensin-converting enzyme inhibitor. The delayed heart to mediastinum count (H/M) ratio, delayed total defect score (TDS) and washout rate were determined from iodine-123 meta-iodobenzylguanidine measured before and 6 months after treatment. Left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV) and LVEF were also determined by echocardiography.

RESULTS

After treatment, in patients receiving torasemide, TDS decreased from 44 (8) to 36 (8) (p < 0.001), H/M ratio increased from 1.61 (0.19) to 1.77 (0.24) (p < 0.001), and washout rate decreased from 52 (12)% to 41 (14)% (p = 0.001). In addition, LVEDV decreased from 173 (22) ml to 147 (30) ml (p < 0.001) and LVESV decreased from 117 (19) ml to 95(24) ml (p < 0.001). Although LVEF tended to increase, the change was not significant (from 31 (7)% to 34 (7)%, NS). Conversely, these parameters did not change significantly in patients receiving furosemide. Moreover, percentage change of TDS was significantly correlated with percentage change of LVEDV (r = 0.473, p < 0.05) and of LVESV (r = 0.579, p < 0.01) after torasemide treatment.

CONCLUSION

These findings indicate that torasemide treatment can ameliorate cardiac sympathetic nerve activity and left ventricular remodelling in patients with CHF.

Effect of parathyroidectomy on cardiac fibrosis and apoptosis: possible role of aldosterone

BACKGROUND/AIM

It has been demonstrated that parathyroidectomy prevents left ventricular hypertrophy in uremic animals. Although this effect may be mediated by direct actions of parathormone (PTH), it may also be exerted through regulation of profibrotic factors such as aldosterone. In adrenal cortex cell cultures, PTH increases aldosterone release. The objective of this work is to assess the effect of parathyroidectomy on aldosterone levels and on cardiac fibrosis and apoptosis in uremic rats.

METHODS

Four groups of rats were studied: C, control; 5/6Nx, 5/6 nephrectomy; PTx, parathyroidectomy, and 5/6NxPTx, 5/6 nephrectomy plus parathyroidectomy. Thirty days after the last surgical procedure the animals were sacrificed. Serum creatinine, ionized calcium, aldosterone, PTH, cardiac weight, fibrosis and apoptosis were measured.

RESULTS

Serum creatinine levels were significantly higher in 5/6Nx and 5/6NxPTx groups (1.62 +/- 0.21 and 1.38 +/- 0.15 mg/dl) than in C and PTx groups (0.66 +/- 0.02 and 0.47 +/- 0.01 mg/dl, p < 0.001). Potassium levels were significantly higher in the 5/6Nx and 5/6NxPTx groups (5.2 +/- 0.3 and 5.4 +/- 0.3 mg/dl) than in the C group (4.3 +/- 0.06 mg/dl, p < 0.05). Values in 5/6Nx and 5/6NxPTx groups were not significantly different from each other. PTH levels were significantly higher in the 5/6Nx group (470.5 +/- 156.3 microg/ml) than in the controls (102.3 +/- 14.3 microg/ml). PTH levels in the PTx group (1.78 +/- 0.52 microg/ml) and in the 5/6NxPTx group (81.64 +/- 32.15 microg/ml) were similar to control values. Ionized calcium was lower in PTx and 5/6NxPTx groups (0.80 +/- 0.07 and 0.89 +/- 0.07 mmol/l) as compared with C and 5/6Nx groups (1.14 +/- 0.01 and 0.96 +/- 0.01 mmol/ l, p < 0.01). The heart weight as percentage of the body weight increased significantly in 5/6Nx animals (4.20 +/- 0.15%) compared to the C group (3.41 +/- 0.27%, p < 0.05); parathyroidectomy reversed the heart weight increment in the 5/6NxPTx animals (3.58 +/- 0.16%). Myocardial fibrosis was significantly higher in the 5/6Nx group (12.5 +/- 1.1%) than in the C group (7.3 +/- 1.5%, p < 0.001); in the 5/6NxPTx animals fibrosis returned towards control values (8.9 +/- 0.2%). Myocardial apoptosis rose significantly in 5/6Nx animals (24.3 +/- 1.2%) compared to the C group (6.7 +/- 0.83%, p < 0.001); parathyroidectomy reversed the apoptosis in the 5/6NxPTx animals (10.4 +/- 0.49%). Aldosterone levels increased significantly in the 5/6Nx group (2,461 +/- 257 pg/ml) compared to the C group (703 +/- 81 pg/ml, p < 0.001); in the 5/6NxPTx animals aldosterone levels were below control values (509 +/- 99 pg/ml).

CONCLUSIONS

Uremia was associated to myocardial hypertrophy, fibrosis and apoptosis. Surgically induced hypoparathyroidism prevented the development of these disorders. Our results suggest that in the remnant kidney rat model myocardial hypertrophy, fibrosis, and apoptosis are mediated by high circulating aldosterone levels. Aldosterone, in turn, may be regulated by PTH.

Circulating biomarkers of extracellular matrix remodeling and risk of atherosclerotic events

PURPOSE OF REVIEW

Disturbances of the synthesis and breakdown of the extracellular matrix of arterial walls have emerged as key features of the atherosclerotic process. Altered levels of circulating extracellular matrix markers have frequently been observed in relation to manifestations of atherosclerotic disease and its risk factors.

RECENT FINDINGS

Research has been focused on the matrix-degrading metalloproteinases, their tissue inhibitors, and procollagen peptides. The most promising matrix metalloproteinase is matrix metalloproteinase-9, which has been observed to predict rapid coronary artery narrowing, ischemic heart disease incidence, abdominal aortic aneurysm expansion, worse outcome in stroke patients, and cardiovascular death. The use of tissue inhibitors of metalloproteinases for prognostication is uncertain thus far. The procollagen marker with most prognostic potential is the marker for type III collagen turnover rate, the N-terminal propeptide PIIINP, higher levels of which predict an adverse outcome after a myocardial infarction and in chronic heart failure, and portend abdominal aortic aneurysm expansion and risk of rupture. Also, the marker for type I collagen synthesis, the C-terminal propeptide PICP, predicts adverse outcomes following myocardial infarction and in chronic heart failure. Extracellular matrix remodeling is also a promising therapeutic target, being favorably affected by several conventional cardiovascular drugs and select dietary interventions. Synthetic matrix metalloproteinase inhibitors are also under development.

SUMMARY

Circulating matrix markers have emerged as candidate biomarkers for predicting risk of subsequent atherosclerotic events. Future large longitudinal observational and intervention studies will determine the role of matrix biomarkers in diagnosis and prognostication, and as targets for intervention in cardiovascular diseases.

Natriuretic peptides: novel therapeutic targets in heart failure

Since the discovery of the cardiac hormone atrial natriuretic peptide by de Bold and colleagues in 1981, the field of natriuretic peptides has significantly advanced with translation of new knowledge to the clinical practice of heart failure. This new knowledge builds on the importance of cardiorenal mechanisms that contribute to optimal cardiovascular regulation. Recent investigations by our group and others have also established the direct myocardial actions of the natriuretic peptides, broadening their therapeutic potential beyond renal mechanisms. Indeed, a potential therapeutic target is cardiac remodeling and fibrosis based on the unique cardiorenal and humoral protective properties that natriuretic peptides possess. We review new insights into the natriuretic peptide system and specifically focus on the possible role of natriuretic peptides as a new therapeutic strategy to limit cardiac remodeling and fibrosis to delay worsening of cardiac function and the progression of heart failure.

La insuficiencia cardíaca en el año 2005

This article is a review of developments reported in the field of heart failure in the last year. It covers advances in epidemiology, pathophysiology and therapy, including cardiac resynchronization therapy and heart transplantation. Today, management of heart failure is complex. It depends on the participation of numerous health professionals under the guidance of a cardiologist. The increasing prevalence of heart failure means that continuing research is mandatory.

New Directions in the Medical Management of Heart Failure

Like the introduction of digitalis more than 200 years ago, novel medical therapies today have the potential to significantly alter the course of heart failure (HF) and save thousands of lives. This review outlines new directions in HF medical management beyond the foundation of neurohormonal blockade. Furthermore, the role of novel risk factors in HF such as chronic renal insufficiency, anemia, and sleep apnea present tantalizing therapeutic targets to extend the morbidity and mortality benefits of current therapies. The course of time will tell which of these risk factors and therapies can hold promise, given the recent litany of negative trials in the HF arena. Advancements in molecular and genetic techniques have allowed us to begin to consider patient specific therapies and lay the groundwork for even further improvements in treatment of symptomatic HF. Finally, advances in telemedicine and device technology will allow the clinician to remotely monitor useful clinical parameters such as heart rate variability and pulmonary filling pressures to make more informed clinical decision-making and improve outcomes.

Effect of MR blockade on collagen formation and cardiovascular disease with a specific emphasis on heart failure

Collagen is the major extracellular matrix protein in the heart and represents a crucial target for anti-remodeling and cardioprotective therapy. Collagen quantity and quality have been shown to be regulated under various physiological and pathologic conditions. Excessive deposition of collagen, leading to cardiac fibrosis, is a major determinant of cardiac dysfunction and arrhythmogenecity associated with sudden death. Serological markers of collagen turnover were proven as a noninvasive reliable tool for monitoring from a distance cardiac tissue repair and fibrosis, both in experimental and clinical conditions. Some markers of collagen synthesis and degradation were shown to have a prognostic significance in myocardial infarction, cardiomyopathy and heart failure, and were reported as independent predictors of mortality. Aldosterone represents the end-product of the renin angiotensin aldosterone system and may play a role in cardiac collagen deposition independent of its effect on blood pressure. Production of aldosterone is mainly regulated by angiotensin II and is activated in the failing human ventricle in proportion to heart failure severity. Circulating or locally produced aldosterone stimulates fibrillar collagen accumulation in the heart directly via mineralocorticoid receptors or, indirectly, modifying angiotensine II receptors number and/or function. The use of mineralocorticoid receptor antagonists counters collagen deposition, even when used on top of classical RAAS inhibitors, such as ACE inhibitors and angiotensine II receptor blockers. There is now accumulating evidence from experimental and clinical studies showing antifibrotic and cardioprotective effect for aldosterone antagonists, spironolactone and eplerenone. In chronic heart failure and post myocardial infarction patients, aldosterone receptor blockade benefit was associated with decreased serum levels of collagen synthesis marker PIIINP (procollagen type III amino-terminal peptide), without affecting collagen degradation. Understanding various autocrine/paracrine mechanisms involved in extracellular matrix remodeling in heart failure represents a major challenge, essential for developing new cardioreparative and cardioprotective strategies.

Early recognition and treatment of hypertensive heart disease

PURPOSE OF REVIEW

Hypertension leads to left ventricular hypertrophy, diastolic dysfunction, and eventually clinical heart failure (hypertensive heart disease). There is an important need for physicians to recognize this entity, understand its pathophysiology, and become fluent in treatment options available. This review of recent basic science and clinical data serves to accomplish this task.

RECENT FINDINGS

In the past year, a number of exciting concepts have come to the forefront. First, data on the use of brain natriuretic peptide as a screening biomarker has shown promise in patients with symptoms of heart failure. For the earliest detection of structural changes, serum propeptide of procollagen type I, a marker of the deposition of type I collagen in the cardiac interstitium provides a noninvasive way to quantify myocardial fibrosis. Treatment options in the past few years have focused heavily on the anti-fibrotic effects of inhibitors of the renin-angiotensin-aldosterone system, perhaps supplanting beta blockers as first-line agents to regress left ventricular hypertrophy. The concept of aldosterone escape is discussed, highlighting the importance of aldosterone inhibitors in these patients. Lastly, we provide a comprehensive review of all antihypertensive classes and their effects on hypertensive heart disease.

SUMMARY

The incidence of hypertensive heart disease is increasing. Earlier detection may be possible with newly studied serum biomarkers. All anti-hypertensive treatments have shown improvement in regressing left ventricular hypertrophy, but inhibitors of the renin-angiotensin-aldosterone system possess the most potent anti-fibrotic effects. It is increasingly important for clinicians to identify and manage hypertensive heart disease to prevent increased morbidity and mortality.

New directions in the assessment and treatment of hypertensive heart disease

PURPOSE OF REVIEW

This article will review briefly the emerging new concepts in the diagnosis and treatment of myocardial fibrosis in patients with hypertensive heart disease.

RECENT FINDINGS

Although hypertensive heart disease is characterized clinically by development of left-ventricular hypertrophy in the absence of a cause other than arterial hypertension, changes in the composition of myocardial tissue also develop in arterial hypertension leading to structural remodeling of the myocardium (e.g. fibrosis). Recent available data on the determination of serum concentrations of collagen-derived serum peptides and quantitative analysis of echoreflectivity to address the presence of fibrosis in the myocardium of hypertensive patients are promising. In addition, preliminary data suggest that the goal of reducing myocardial fibrosis is achievable in patients with hypertensive heart disease using specific antihypertensive agents (e.g. those interfering with angiotensin II).

SUMMARY

The time has come to revisit the current management of hypertensive heart disease simply focused on detecting left-ventricular hypertrophy and controlling blood pressure to reduce left-ventricular mass. It is necessary to develop new approaches aimed at assessing and repairing alterations of myocardial structure and protect myocardial function and, in so doing, to reduce in a more-effective manner adverse risk associated with hypertensive heart disease.

The use of collagen-derived serum peptides for the clinical assessment of hypertensive heart disease

Given the importance of fibrous tissue in leading to myocardial dysfunction and failure in hypertensive heart disease, non-invasive assessment of fibrosis could prove a clinically useful tool in hypertensive patients, particularly given the potential for cardioprotective and cardioreparative pharmacological strategies. In this regard, an emerging experimental and clinical experience holds promise for the assessment of various serum peptides arising from the metabolism of collagen types I and III in arterial hypertension. More specifically, the measurement of serum concentrations of procollagen type I carboxy-terminal propeptide (a peptide that is cleaved from procollagen type I during the synthesis of fibril-forming collagen type I) may provide indirect diagnostic information on both the extent of myocardial fibrosis and the ability of antihypertensive treatment to diminish collagen type I synthesis and reduce myocardial fibrosis in hypertensive patients. The available data set the stage for large and long-term trials to definitively validate this approach.