Diagnostic Utility of Plasma N-Terminal Pro-B-Type Natriuretic Peptide and C-Reactive Protein Levels in Differential Diagnosis of Pericardial Constriction and Restrictive Cardiomyopathy

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

Natriuretic peptides to differentiate constrictive pericarditis and restrictive cardiomyopathy: A systematic review and meta-analysis

Previous studies have shown that natriuretic peptide levels are increased in patients with restrictive cardiomyopathy (RCM) but not in constrictive pericarditis (CP). We performed a systematic review and meta-analysis to evaluate the diagnostic utility of B-type natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) to differentiate CP and RCM. We searched electronic databases from inception to January 07, 2021. Studies involving adult patients that assessed the utility of natriuretic peptides to differentiate CP and RCM were included. All meta-analyses were performed using a random-effects model. Seven studies (four case-control and three cohorts) involving 204 patients were included. The mean age ranged between 25.7 and 64.1 years and 77% of patients were men. BNP levels were significantly lower (standardized median difference [SMD], -1.48; 95% confidence interval [CI], -2.33 to -0.63) in patients with CP compared to RCM. The pooled area under the curve (AUC) of the BNP level was 0.81 (95% CI, 0.70-0.92). NT-proBNP (SMD, -0.86; 95% CI, -1.38 to -0.33) and log NT-proBNP (SMD, -1.89; 95% CI, -2.59 to -1.20) levels were significantly lower in patients with CP compared to RCM. Our review shows that BNP and NT-proBNP levels were significantly lower in patients with CP compared to RCM. The pooled AUC of BNP level showed a good diagnostic accuracy to differentiate both conditions.

Heart failure with preserved ejection fraction

Many patients with heart failure (HF) have a normal left ventricular ejection fraction, and are labelled as having HF with preserved left ventricular ejection fraction (HFPEF). Hypertension, atrial fibrillation and age are important contributors to the development of HFPEF and, therefore, its prevalence is likely to increase in the next few decades. The pathophysiology of HFPEF is heterogeneous but with a final common pathway leading to congestion. HF remains a clinical diagnosis but the plasma concentration of B-type natriuretic peptide (eg BNP/N-terminal prohormone BNP (NT-proBNP)), a marker of congestion, is an essential component. Imaging, usually by echocardiography, is required to determine the cardiac phenotype (ie valve disease, left ventricular ejection fraction) underlying HF. A superficially normal echocardiogram does not exclude a diagnosis of HF. No treatment has been shown conclusively to alter the prognosis of HFPEF. However, treatments directed at congestion and hypertension, such as diuretics, mineralocorticoid receptor antagonists (MRAs) and angiotensin converting-enzyme inhibitors, may improve symptoms and probably do improve outcomes. No treatment has yet been shown to reverse the underlying myocardial pathology of HFPEF, although there is some hope that MRAs might.

[Constrictive pericarditis - new methods in the diagnosis of an old disease: a case report]

Constrictive pericarditis is a rare clinical entity that can pose diagnostic problems. The gold standard for diagnosis is cardiac catheterization with analysis of intracavitary pressure curves, which are high and, in end-diastole, equal in all chambers. The diastolic profile in both ventricles presents the classic dip-and-plateau pattern and the difference between the diastolic pressures of both ventricles should not exceed 3-5mmHg. Unfortunately, these traditional criteria are not always present and in fact the sensitivity and specificity of equalization of diastolic pressures are relatively low and of limited value in individual patients. This highlights the need to use new cardiac imaging techniques to resolve any doubts. The case described here is a good example.