Chagas Cardiomyopathy and Myocardial Sympathetic Denervation

PURPOSE OF REVIEW

More than a century since its discovery, the pathogenesis of Chagas heart disease (CHD) remains incompletely understood. The role of derangements in the autonomic control of the heart in triggering malignant arrhythmia before the appearance of contractile ventricular impairment was reviewed.

RECENT FINDINGS

Although previous investigations had demonstrated the anatomical and functional consequences of parasympathetic dysautonomia upon the heart rate control, only recently, coronary microvascular disturbances and sympathetic denervation at the ventricular level have been reported in patients and experimental models of CHD, exploring with nuclear medicine methods their impact on the progression of myocardial dysfunction and cardiac arrhythmias. More important than parasympathetic impaired sinus node regulation, recent evidence indicates that myocardial sympathetic denervation associated with coronary microvascular derangements is causally related to myocardial injury and arrhythmia in CHD. Additionally, 123I-MIBG imaging is a promising tool for risk stratification of progression of ventricular dysfunction and sudden death.

Surgical waiting lists and queue management in a Brazilian tertiary public hospital

BACKGROUND

Centralized management of queues helps to reduce the surgical waiting time in the publicly funded healthcare system, but this is not a reality in the Brazilian Unified Healthcare System (BUHS). We describe the implementation of the "Patients with Surgical Indication" (PSI) in a Brazilian public tertiary hospital, the impact on waiting time, and its use in rationing oncological surgeries during the COVID-19 Pandemic.

METHODS

Retrospective observational study of elective surgical requests (2016-2022) in a Brazilian general, public, tertiary university hospital. We recovered information regarding the inflows (indications), outflows and their reasons, the number of patients, and waiting time in queue.

RESULTS

We enrolled 82,844 indications in the PSI (2016-2022). The waiting time (median and interquartile range) in days decreased from 98(48;168) in 2016 to 14(3;152) in 2022 (p < 0.01). The same occurred with the backlog that ranged from 6,884 in 2016 to 844 in 2022 (p < 001). During the Pandemic, there was a reduction in the number of non-oncological surgeries per month (95% confidence interval) of -10.9(-18.0;-3.8) during Phase I (January 2019-March 2020), maintenance in Phase II (April 2020-August 2021) 0.1(-10.0;10.4) and increment in Phase III (September 2021-December 2022) of 23.0(15.3;30.8). In the oncological conditions, these numbers were 0.6(-2.1;3.3) for Phase I, an increase of 3.2(0.7;5.6) in Phase II and 3.9(1,4;6,4) in Phase III.

CONCLUSION

Implementing a centralized list of surgical indications and developing queue management principles proved feasible, with effective rationing. It unprecedentedly demonstrated the decrease in the median waiting time in Brazil.

Cardiac Magnetic Resonance as an Etiological Diagnosis Tool in Recovered Sudden Cardiac Death or Unstable Ventricular Arrhythmia Patients

BACKGROUND

Cardiac magnetic resonance (CMR) has an increasing diagnostic relevance in survivors of sudden cardiac death (SCD) or unstable ventricular arrhythmia (UVA) in developed countries.

OBJECTIVE

To evaluate retrospectively the additional role of CMR in a developing country where few resources are available, and should be used more effectively.

METHODS

The study included SCD or UVA survivors admitted between 2009 and 2019 at a tertiary academic institution referred to CMR. Demographic, clinical, and laboratory data were collected from the medical records. CMR images and reports were reviewed and their impact on the final etiological diagnosis was determined. A descriptive analysis was performed and p<0.05 established as significant.

RESULTS

Sixty-four patients, 54.9±15.4 years old, and 42 (71.9%) males. Most events (81.3%) were out of the hospital and ventricular tachycardia was the most common rhythm. Cardiovascular medications were previously used by 55 patients, and beta-blockers were the most used medications (37.5%). Electrocardiogram had electrical inactive areas in 21.9% and all of them had fibrosis at CMR. Mean left ventricular ejection fraction (LVEF) was 44±14%, with 60.9% ≤50% and only 29.7% ≤35%. Late gadolinium enhancement was identified in 71.9%, with a transmural pattern in 43.8%. Chagas cardiomyopathy was the most common etiology (28.1%), followed by ischemic cardiomyopathy (17.2%). Among 26 without a previously identified etiology, CMR could define it (15 patients - 57%).

CONCLUSION

In accordance with previous studies in developed countries, CMR was capable of increasing etiological diagnosis and identifying the arrhythmogenic substrate, allowing better care in half of the underdiagnosed patients.

Regional myocardial sympathetic denervation precedes the development of left ventricular systolic dysfunction in chronic Chagas' cardiomyopathy

BACKGROUND

Regional myocardial sympathetic denervation is a conspicuous and early disorder in patients with chronic Chagas' cardiomyopathy (CCC), potentially associated to the progression of myocardial dysfunction OBJECTIVE: To evaluate in a longitudinal study the association between the presence and the progression of regional myocardial sympathetic denervation with the deterioration of global and segmental left ventricular dysfunction in CCC.

METHODS

18 patients with CCC were submitted at initial evaluation and after 5.5 years to rest myocardial scintigraphy with 123Iodo-metaiodobenzylguanidine and 99mTc-sestamibi and to two-dimensional echocardiography to assess myocardial sympathetic denervation, extent of fibrosis, and the left ventricular ejection fraction (LVEF) and wall motion abnormalities.

RESULTS

In the follow-up evaluation, compared to the initial one, we observed a significant decrease in LVEF (56 ± 11 to 49% ± 12; P = .01) and increased summed defects scores in the myocardial innervation scintigraphy (15 ± 10 to 20 ± 9; P < .01). The presence of regional myocardial sympathetic denervation in ventricular regions of viable non-fibrotic myocardium presented an odds ratio of 4.25 for the development of new wall motion abnormalities (P = .001).

CONCLUSION

Regional and global myocardial sympathetic denervation is a progressive derangement in CCC. In addition, the regional denervation is topographically associated with areas of future development of regional systolic dysfunction in patients with CCC.

Association of left ventricular abnormalities with incident cerebrovascular events and sources of thromboembolism in patients with chronic Chagas cardiomyopathy

BACKGROUND

Although Chagas cardiomyopathy is related to thromboembolic stroke, data on risk factors for cerebrovascular events in Chagas disease is limited. Thus, we assessed the relationship between left ventricular (LV) impairment and cerebrovascular events and sources of thromboembolism in patients with Chagas cardiomyopathy.

METHODS

This retrospective cohort included patients with chronic Chagas cardiomyopathy who underwent cardiovascular magnetic resonance (CMR). CMR was performed with a 1.5 T scanner to provide LV volumes, mass, ejection fraction (LVEF), and myocardial fibrosis. The primary outcome was a composite of incident ischemic cerebrovascular events (stroke or transient ischemic attack-TIA) and potential thromboembolic sources (atrial fibrillation (AF), atrial flutter, or intracavitary thrombus) during the follow-up.

RESULTS

A total of 113 patients were included. Median age was 56 years (IQR: 45-67), and 58 (51%) were women. The median LVEF was 53% (IQR: 41-62). LV aneurysms and LV fibrosis were present in 38 (34%) and 76 (67%) individuals, respectively. The median follow-up time was 6.9 years, with 29 events: 11 cerebrovascular events, 16 had AF or atrial flutter, and two had LV apical thrombosis. In the multivariable model, only lower LVEF remained significantly associated with the outcomes (HR: 0.96, 95% CI: 0.93-0.99). Patients with reduced LVEF lower than 40% had a much higher risk of cerebrovascular events and thromboembolic sources (HR: 3.16 95% CI: 1.38-7.25) than those with normal LVEF. The combined incidence rate of the combined events in chronic Chagas cardiomyopathy patients with reduced LVEF was 13.9 new cases per 100 persons-year.

CONCLUSIONS

LV systolic dysfunction is an independent predictor of adverse cerebrovascular events and potential sources of thromboembolism in patients with chronic Chagas cardiomyopathy.

Statins Prescriptions and Lipid Levels in a Tertiary Public Hospital

BACKGROUND

The development of a new class of medications that are highly capable of reducing LDL-cholesterol renewed the interest in the characterization of familial hypercholesterolemia patients. Nevertheless, little is known about the lipid profile of patients in tertiary healthcare centers in Brazil in order to better estimate the real occurrence of familial hypercholesterolemia, with initial suspect of LDL-cholesterol levels above 190 mg/d/L.

OBJECTIVES

This study evaluated the lipid profile (total cholesterol and LDL-cholesterol) in ambulatory patients from a general tertiary public hospital.

METHODS

Retrospective study comparing prescriptions of statins and lipid profile results. The significance level was established in 5%.

RESULTS

In one year, 9,594 individuals received statin prescriptions, of whom 51.5% were females and the mean age was 63.7±12.9 years-old (18 to 100 years-old). Thirty-two medical specialties prescribed statins. Cardiology was responsible for 43% of the total. Nearly 15% of those patients with a prescription did not have a recent total cholesterol result and 1,746 (18%) did not have a recent LDL-cholesterol measurement. The occurrence of the latter between 130 and 190 mg/dL was present in 1,643 (17.1%) individuals, and 228 (2.4%) patients had an LDL-cholesterol ≥190mg/dL among those using statins at distinct doses. Only two statins were used: simvastatin and atorvastatin. The first was prescribed in 77.6% of the prescriptions.

CONCLUSION

In this cross-sectional cohort at a tertiary general hospital, statins have been widely prescribed but with little success in achieving recognized levels of control. There is probably a significant number of FH individuals in this cohort that need to be properly diagnosed in order to receive adequate treatment due to its prognostic implications.

Correlation between Cardiomegaly on Chest X-Ray and Left Ventricular Diameter on Echocardiography in Patients with Chagas Disease

Fundamento

Cardiomegalia pela radiografia de tórax (RXT) é preditor independente de morte em indivíduos com cardiomiopatia crônica da doença de Chagas (CCDC). Contudo, a correlação entre o aumento do índice cardiotorácico (ICT) na RXT e do diâmetro telediastólico do ventrículo esquerdo (DDVE) pela ecocardiografia (ECO) nessa população não está bem definida.

Objetivos

Analisar a relação entre cardiomegalia pela RXT e DDVE pela ECO em pacientes com doença de Chagas (DC) e sua aplicabilidade ao escore de Rassi.

Métodos

Estudo retrospectivo incluiu 63 pacientes ambulatoriais com DC avaliados por RXT e ECO. Cardiomegalia na RXT foi definida como ICT > 0,5. DDVE foi avaliado como variável contínua. Curva ROC foi utilizada para avaliar o potencial do DDVE para identificação de cardiomegalia pela RXT, com ponto de corte definido pela maior somatória de sensibilidade e especificidade.

Resultados

Idade mediana = 61 anos [intervalo interquartil: 48-68], 56% mulheres. CCDC foi identificada em 58 pacientes; 5 tinham a forma indeterminada da DC. Cardiomegalia foi detectada em 28 indivíduos. A área sob a curva ROC do DDVE para identificação de cardiomegalia foi de 0,806 (IC 95%: 0,692-0,919). O ponto de corte ótimo para DDVE foi de 60 mm (sensibilidade = 64%, especificidade = 89%). O uso do DDVE pela ECO em substituição ao ICT pela RXT alterou o escore de Rassi em 14 pacientes, e em 10 deles houve redução do risco presumido.

Conclusão

DDVE pela ECO é parâmetro adequado e com alta especificidade para distinguir entre presença e ausência de cardiomegalia na RXT na DC. (Arq Bras Cardiol. 2021; 116(1):68-74)

Sudden cardiac death in Brazil: a community-based autopsy series (2006-2010)

Background

Sudden cardiac death (SCD) is a sudden unexpected event, from a cardiac cause, that occurs in less than one hour after the symptoms onset, in a person without any previous condition that would seem fatal or who was seen without any symptoms 24 hours before found dead. Although it is a relatively frequent event, there are only few reliable data in underdeveloped countries.

Objective

We aimed to describe the features of SCD in Ribeirão Preto, Brazil (600,000 residents) according to Coroners’ Office autopsy reports.

Methods

We retrospectively reviewed 4501 autopsy reports between 2006 and 2010, to identify cases of SCD. Specific cause of death as well as demographic information, date, location and time of the event, comorbidities and whether cardiopulmonary resuscitation (CPR) was attempted were collected.

Results

We identified 899 cases of SCD (20%); the rate was 30/100000 residents per year. The vast majority of cases of SCD involved a coronary artery disease (CAD) (64%) and occurred in men (67%), between the 6^th and the 7^th decades of life. Most events occurred during the morning in the home setting (53.3%) and CPR was attempted in almost half of victims (49.7%). The most prevalent comorbidity was systemic hypertension (57.3%). Chagas’ disease was present in 49 cases (5.5%).

Conclusion

The majority of victims of SCD were men, in their sixties and seventies and the main cause of death was CAD. Chagas’ disease, an important public health problem in Latin America, was found in about 5.5% of the cases.

Number of P-wave fragmentations on P-SAECG correlates with infiltrated atrial fat

BACKGROUND

Although atrial fibrillation (AF) triggers are known, the underlying AF substrate is less well understood. The goal of our study was to explore correlations between electrophysiological and structural characteristics of atria in patients with paroxysmal AF and individuals at AF risk.

METHODS

Patients in sinus rhythm (N = 90; age 57 ± 10 year; 55 men [63.2%]) with structural heart disease and paroxysmal AF (n = 12 [13%]), or with AF risk factors and LVEF > 35% (n = 78), underwent SAECG and cardiac magnetic resonance study. Interatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. All local P-wave extrema were identified on SAECG leads during sinus rhythm. A P-wave fragmentation (Pf) was defined as an absolute difference between adjacent extrema which was above three standard deviations of noise, and was normalized by the duration of the P wave in the corresponding lead.

RESULTS

The Pf was greater on the filtered than on the unfiltered P-SAECG signal (13.1 ± 3.8 vs. 3.4 ± 1.2; P < 0.0001). Pf was the greatest on the Y lead (13.0 ± 3.5 on Y lead vs. 12.1 ± 3.4 on Z lead; P = 0.003. Pf on Z lead correlated with interatrial fat index (r = 0.544; P = 0.001). Epicardial fat significantly correlated with body mass index (BMI; r = 0.302; P = 0.015). After adjustment for BMI, left atrium (LA) size, epicardial fat, and interatrial septum width, interatrial fat independently associated with the Pf on Z lead (β-coefficient 0.009 [95%CI 0.0003-0.019]; P = 0.043).

CONCLUSIONS

Infiltrated atrial fat correlates with discontinuous conduction on posterior LA wall and represents AF early substrate.

Infiltrated atrial fat characterizes underlying atrial fibrillation substrate in patients at risk as defined by the ARIC atrial fibrillation risk score

BACKGROUND

It is known that expanded epicardial fat is associated with atrial fibrillation (AF). However, infiltrated intraatrial fat has not been previously quantified in individuals at risk as determined by the ARIC AF risk score.

METHODS

Patients in sinus rhythm (N=90, age 57 ± 10 years; 55 men [63.2%]), in 3 groups at risk of AF as determined by the ARIC AF risk score [low (≤ 11 points; n=15), moderate (12-18 points; n=40), high (≥ 19 points; n=23) risk of AF], and paroxysmal AF (n=12) underwent cardiac magnetic resonance study. Intraatrial and epicardial fat was analyzed with a Dark-blood DIR-prepared Fat-Water-separated sequence in the horizontal longitudinal axis. OsiriX DICOM viewer (Geneva, Switzerland) was used to quantify the intraatrial fat area. Width of the cephalad portion of the interatrial septum was measured at the level of the fossa ovalis.

RESULTS

Intraatrial fat monotonically increased with growing AF risk in study groups (low AF risk 16 ± 4 vs. moderate AF risk 32 ± 18 vs. high AF risk 81 ± 83 mm(2); ANOVA P=0.012). Log-transformed intraatrial fat predicted ARIC AF risk score in multivariate ordered probit regression after adjustment for sex, race, left and right atrial area indices, and body mass index (β-coefficient 0.50 [95% CI 0.03-0.97]; P=0.037), whereas epicardial fat did not. Interatrial septum width showed similar association (3.0 ± 1.4 vs. 5.0 ± 1.8 vs. 7.1 ± 2.7 mm; ANOVA P<0.001; adjusted β-coefficient 2.80 [95% CI 1.19-4.41]; P=0.001).

CONCLUSIONS

Infiltrated intraatrial fat characterizes evolving substrate in individuals at risk of AF.

Magnetic resonance imaging evaluation of cardiac masses

Background

Cardiac tumors are extremely rare; however, when there is clinical suspicion, proper diagnostic evaluation is necessary to plan the most appropriate treatment. In this context, cardiovascular magnetic resonance imaging (CMRI) plays an important role, allowing a comprehensive characterization of such lesions.

Objective

To review cases referred to a CMRI Department for investigation of cardiac and paracardiac masses. To describe the positive case series with a brief review of the literature for each type of lesion and the role of cardiovascular magnetic resonance imaging in evaluation.

Methods

Between August 2008 and December 2011, all cases referred for CMRI with suspicion of tumor involving the heart were reviewed. Cases with positive histopathological diagnosis, clinical evolution or therapeutic response compatible with the clinical suspicion and imaging findings were selected.

Results

Among the 13 cases included in our study, eight (62%) had histopathological confirmation. We describe five benign tumors (myxomas, rhabdomyoma and fibromas), five malignancies (sarcoma, lymphoma, Richter syndrome involving the heart and metastatic disease) and three non-neoplastic lesions (pericardial cyst, intracardiac thrombus and infectious vegetation).

Conclusion

CMRI plays an important role in the evaluation of cardiac masses of non-neoplastic and neoplastic origin, contributing to a more accurate diagnosis in a noninvasive manner and assisting in treatment planning, allowing safe clinical follow-up with good reproducibility.

Evaluation of cardiac involvement during dengue viral infection

BACKGROUND

 Dengue is a disease whose clinical manifestations range from asymptomatic infections to a severe disease. There have been some previous reports of myocardial involvement in dengue, but this association has not been completely established.

METHODS

 From January to July of 2011, patients hospitalized with dengue, confirmed through dengue nonstructural protein 1 and/or immunoglobulin M detection, were included in this study and troponin I and N terminal fragment of B-type natriuretic peptide levels were determined. Patients with abnormal biomarkers underwent echocardiography and when any abnormality was detected, they underwent cardiac magnetic resonance imaging.

RESULTS

 Eighty-one patients were evaluated and 12 patients (15%) presented with elevated biomarker levels. Compared to controls, they had higher leukocyte (P < .001) and platelet counts (P = .005); higher C-reactive protein (P = .02), and a lower viral load (P = .03). There was no difference according to clinical dengue classification; dengue hemorrhagic fever/dengue shock syndrome severity; duration of symptoms; or prevalence of secondary infection between the 2 groups. Two patients died secondary to cardiogenic shock before imaging studies. Necroscopic findings were compatible to myocarditis in both, and immunohistochemistry for dengue virus showed increased staining on mononuclear cells located in the myocardial tissue. Of the 10 patients who underwent echocardiography, depressed left ventricular ejection fraction (LVEF) was identified in 1, left ventricular segmental abnormalities with preserved LVEF in 2, and an important pericardial effusion with tamponade in another. Cardiac involvement was confirmed by CMR in these 4 patients.

CONCLUSIONS

 Dengue viruses were shown to cause cardiac disease with clinical manifestations ranging from mild elevation of biomarkers to myocarditis and/or pericarditis.

Ultrasonic tissue characterization in acute coronary syndromes

BACKGROUND

Ultrasonic tissue characterization (UTC), as evaluated through integrated backscatter, has the potential to detect precocious structural damage to myocardial tissue. In acute coronary syndromes (ACS) this technique is attracting attention due to its potential to evaluate myocardial viability.

OBJECTIVE

To evaluate the role of UTC in the emergency department.

METHODS

We studied 28 individuals, classified in three groups: Group I (13; 52.2+/-15.5 years) with patients admitted with chest pain who have negative evaluation for acute coronary syndrome; Group II (9; 54.2+/-10.0 years) with acute myocardial infarction in right coronary artery territory; and Group III (6; 62.1+/-9.1 years) with acute myocardial infarction in the anterior descendent branch territory. For each individual, we analyzed four segments in the short axis view at the papillary muscle level (1--anterior; 2--anterior-lateral; 3--inferior e 4--septal), for the following parameters: corrected coefficient, amplitude, delay index and IBS pattern.

RESULTS

The acute myocardial isquemic process in its initial phase was not detected by the corrected coefficient or by the IBS amplitude. The sincronicity parameters (delay index and IBS pattern), more sensible, were partially able to identify changes in more extension regions of myocardial infarction.

CONCLUSION

More studies should be conducted to evaluate these parameters in the early phase of acute coronary syndromes.