N-terminal pro-brain natriuretic peptide in newly diagnosed acromegaly

Serum NT-pro-BNP Levels Predict Cardiovascular Events in Acromegaly Patients

Background Acromegaly is associated with an increased risk of fatal and non-fatal cardiovascular (CV) events. Controlling acromegaly decreases, but does not normalize this risk. Brain natriuretic peptide (BNP) assessment is used in the general population for the diagnosis of heart failure and to predict ischemic recurrences and mortality. This is a retrospective, longitudinal, monocenter study that evaluates the role of serum N-terminal fragment of BNP (NT-pro-BNP) for predicting CV events in acromegaly patients.

Methods Serum NT-pro-BNP levels were measured in 76 patients with acromegaly (23 males, 57.7±1.5 years), and compared with other predictors of CV events. NT-pro-BNP cut-off value discriminating the occurrence of CV events was determined by ROC analysis. CV events were recorded during a follow-up of 78.6±6.4 months.

Results CV events occurred in 9.2% of patients. Mean log(NT-pro-BNP) concentration was higher in patients who experienced CV events than in those who did not (p<0.01) and in patients who died due to CV events than in those who died due to other causes (p<0.01). Based on the ROC curve, a cut-off value of 91.55 pg/mL could predict CV events (OR 19.06). Log(NT-pro-BNP) was lower in surgically treated patients by surgery (p<0.05), and in those cured by neurosurgery (p<0.02).

Conclusions High NT-pro-BNP value is an independent middle-term predictor of fatal or non-fatal CV events in patients with acromegaly. According to this parameter, surgically treated patients show lower CV risk than those managed with medical therapy, especially if the disease is cured.

Acromegaly and Heart Failure

In patients with acromegaly, chronic GH and IGF-I excess commonly causes a specific cardiomyopathy characterized by a concentric cardiac hypertrophy associated with diastolic dysfunction and, in later stages, with systolic dysfunction ending in heart failure in untreated and uncontrolled patients. Additional relevant cardiovascular complications are represented by arterial hypertension, valvulopathies, arrhythmias, and vascular endothelial dysfunction, which, together with the respiratory and metabolic complications, contribute to the development of cardiac disease and the increase cardiovascular risk in acromegaly. Disease duration plays a pivotal role in the determination of acromegalic cardiomyopathy. The main functional disturbance in acromegalic cardiomyopathy is the diastolic dysfunction, observed in 11% to 58% of patients, it is usually mild, without clinical consequence, and the progression to systolic dysfunction is generally uncommon, not seen or observed in less than 3% of the patients. Consequently, the presence of overt CHF is rare in acromegaly, ranging between 1 and 4%, in patients with untreated and uncontrolled disease. Control of acromegaly, induced by either pituitary surgery or medical therapy improves cardiac structure and performance, limiting the progression of acromegaly cardiomyopathy to CHF. However, when CHF is associated with dilative cardiomyopathy, it is generally not reversible, despite the treatment of the acromegaly.

Risk of left ventricular hypertrophy and diastolic and systolic dysfunction in Acromegaly: A meta-analysis

OBJECTIVE

To perform a meta-analysis to evaluate the exact incidence of left ventricular hypertrophy, diastolic dysfunction and systolic dysfunction in patients with treatment-naïve acromegaly.

METHODS

PubMed, EMBASE, Ovid MEDLINE, the Cochrane Library, Scopus, Science Citation Index Expand and PubMed Central were searched for eligible studies. Eligible data were extracted and evaluated using a fixed- or random-effects model. The Q test, I² statistics for testing heterogeneity, the Newcastle-Ottawa Scale (NOS) for the retrospective appraisal of study quality, and Begg's test and Harbord's modified test for the evaluation of publication bias were used.

RESULTS

Seven eligible studies were selected, and a total of 458 patients and 650 controls were included. Left ventricular hypertrophy was significantly more frequent in treatment-naïve acromegaly patients than in controls [odds ratio (OR) = 28.2, 95% confidence interval (CI) = 19.17-41.49] with a prevalence of 65.1%. Diastolic dysfunction was also common (50.5%) in acromegaly patients (OR = 15.62, 95% CI = 1.98-123.34). Moreover, 19.6% of patients presented abnormal systolic function with an OR of 13.1 (95% CI = 6.64-25.84).

CONCLUSIONS

Patients with treatment-naïve acromegaly are at an increased risk of developing left ventricular hypertrophy, diastolic dysfunction and systolic dysfunction than the general population.

Active acromegaly is associated with decreased hs-CRP and NT-proBNP serum levels: insights from the Belgian registry of acromegaly

OBJECTIVE

Patients with active acromegaly have an increased prevalence of cardiomyopathy and heart failure but a less than expected risk of coronary artery disease, considering the frequent association of diabetes mellitus and hypertension. We examined whether changes in high-sensitive C-reactive protein (hs-CRP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) might contribute to this phenomenon.

DESIGN AND METHODS

Two hundred patients of the Belgian acromegaly registry (AcroBel) were divided in two groups: active disease (IGF1 Z-score >2; n=95) and controlled disease (IGF1 Z-score ≤2; n=105). Serum levels of hs-CRP and NT-proBNP were measured and correlated with BMI, blood pressure, fasting lipids, fasting glucose and insulin, HbA1c, IGF1, interleukin 6 (IL6), adiponectin, and sE-selectin. In a subset of acromegaly patients, hs-CRP, IL6, and NT-proBNP levels were also compared with those/the values of an age-, gender-, and BMI-matched reference group.

RESULTS

Patients with active acromegaly had significantly lower levels of hs-CRP (median (interquartile range), 0.5 mg/l (0.1, 0.9) vs 1.3 mg/l (0.5, 4.1); P<0.001) and NT-proBNP, (47.0 ng/l (26.0, 86.0) vs 71.0 ng/l (43.0, 184.0); P<0.001) compared with patients with controlled acromegaly. Compared with the reference population, hs-CRP was not different in controlled acromegaly but significantly lower in active acromegaly (median, 0.4 mg/l (0.1, 0.8) vs 1.4 mg/l (0.8, 2.9); P<0.001), while NT-proBNP was similar in active acromegaly but significantly higher in controlled acromegaly (66.5 ng/l (40.0, 119.5) vs 50.8 ng/l (26.5, 79.7); P<0.001).

CONCLUSIONS

Patients with active acromegaly have significantly lower values of NT-proBNP and hs-CRP compared with patients with controlled disease and even lower values of hs-CRP compared with control subjects.