Exercise Oscillatory Ventilation Improves Heart Failure Prognostic Scores.

BACKGROUND: Several heart failure (HF) prognostic risk scores are available to guide the ideal time for listing candidates for a heart transplant (HTx). The detection of exercise oscillatory ventilation (EOV) during cardiopulmonary exercise testing (CPET) is associated with advanced HF and a worse prognosis, and yet it is not accounted for in these risk scores. Therefore, this study aimed to assess whether EOV further adds prognostic value to HF scores. METHODS: A single-centre retrospective cohort study was undertaken of consecutive HF patients with reduced ejection fraction (HFrEF) who underwent CPET from 1996 to 2018. The Heart Failure Survival Score (HFSS), Seattle Heart Failure Model (SHFM), Meta-analysis Global Group In Chronic Heart Failure (MAGGIC), and Metabolic Exercise Cardiac Kidney Index (MECKI) were calculated. The added value of EOV on top of those scores was assessed using a Cox proportional hazard model. The added discriminative power was also assessed by receiver operating characteristic curve comparison. RESULTS: A total of 390 HF patients with a median age of 58 (IQR 50-65) years were investigated, of whom 78% were male and 54% had ischaemic heart disease. The median peak oxygen consumption was 15.7 mL/kg/min (IQR 12.8-20.1). Exercise oscillatory ventilation was detected in 153 (39.2%) patients. Over a median follow-up of 2 years, 61 patients died (49 due to a cardiovascular reason) and 54 had a HTx. Exercise oscillatory ventilation independently predicted the composite outcome of all-cause death and HTx. Furthermore, the presence of this ventilatory pattern significantly improved the prognostic performance of both HFSS and MAGGIC scores. CONCLUSION: Exercise oscillatory ventilation was often found in a cohort of HF patients with reduced LVEF who underwent CPET. It was found that EOV added further prognostic value to contemporary HF scores, suggesting that this easily obtained parameter should be included in future modified HF scores.

Severe hypoxemia in a patient with right ventricular myocardial infarction and SARS-CoV-2 infection.

BACKGROUND: Refractory hypoxemia after right ventricular myocardial infarction and concomitant SARS-CoV-2 infection represents an uncommon, yet particularly challenging clinical scenario. We report a challenging diagnostic case of refractory hypoxemia due to right-to-left shunt highlighting contemporary challenges and pitfalls in acute cardiovascular care associated with the current COVID-19 pandemic. CASE PRESENTATION: A 52-year-old patient admitted for inferior acute myocardial infarction developed rapidly worsening hypoxemia shortly after primary percutaneous coronary intervention. RT-PCR screening for SARS-CoV-2 was positive, even though the patient had no prior symptoms. A computed tomography pulmonary angiogram excluded pulmonary embolism and showed only mild interstitial pulmonary involvement of the virus. Transthoracic echocardiogram showed severe right ventricular dysfunction and significant right-to-left shunt at the atrial level after agitated saline injection. Progressive improvement of right ventricular function allowed weaning from supplementary oxygen support. Patient was latter discharged with marked symptomatic improvement. CONCLUSION: Refractory hypoxemia after RV myocardial infarction should be carefully addressed, even in the setting of other more common and tempting diagnoses. After exclusion of usual etiologies, right-to-left shunting at the atrial level should always be suspected, as this may avoid unnecessary and sometimes harmful interventions.

Pectoralis major muscle quantification by cardiac MRI is a strong predictor of major events in HF.

Clinical overt cardiac cachexia is a late ominous sign in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF). The main goal of this study was to assess the feasibility and prognostic significance of muscle mass quantification by cardiac magnetic resonance (CMR) in HF with reduced LVEF. HF patients with LVEF < 40% (HFrEF) referred for CMR were retrospectively identified in a single center. Key exclusion criteria were primary muscle disease, known infiltrative myocardial disease and intracardiac devices. Pectoralis major muscles were measured on standard axial images at the level of the 3rd rib anteriorly. Time to all-cause death or HF hospitalization was the primary endpoint. A total of 298 HF patients were included (mean age 64 ± 12 years; 76% male; mean LVEF 30 ± 8%). During a median follow-up of 22 months (IQR: 12-33), 67 (22.5%) patients met the primary endpoint (33 died and 45 had at least 1 HF hospitalization). In multivariate analysis, LVEF [Hazard Ratio (HR): 0.950; 95% Confidence Interval (CI): 0.917-0.983; p = 0.003), NYHA class I-II vs III-IV (HR: 0.480; CI: 0.272-0.842; p = 0.010), creatinine (HR: 2.653; CI: 1.548-4.545; p < 0.001) and pectoralis major area (HR: 0.873; 95% CI: 0.821-0.929; p < 0.001) were independent predictors of the primary endpoint, when adjusted for gender and NT-pro-BNP levels. Pectoralis major size measured by CMR in HFrEF was independently associated with a higher risk of death or HF hospitalization. Further studies to establish appropriate age and gender-adjusted cut-offs of muscle areas are needed to identify high-risk subgroups.

Early changes in diaphragmatic function evaluated using ultrasound in cardiac surgery patients: a cohort study.

Little is known about the evolution of diaphragmatic function in the early post-cardiac surgery period. The main purpose of this work is to describe its evolution using ultrasound measurements of muscular excursion and thickening fraction (TF). Single-center prospective study of 79 consecutive uncomplicated elective cardiac surgery patients, using motion-mode during quiet unassisted breathing. Excursion and TF were measured sequentially for each patient [pre-operative (D1), 1 day (D2) and 5 days (D3) after surgery]. Pre-operative median for right and left hemidiaphragmatic excursions were 1.8 (IQR 1.6 to 2.1) cm and 1.7 (1.4 to 2.0) cm, respectively. Pre-operative median right and left thickening fractions were 28 (19 to 36) % and 33 (22 to 51) %, respectively. At D2, there was a reduction in both excursion (right: 1.5 (1.1 to 1.8) cm, p < 0.001, left: 1.5 (1.1 to 1.8), p = 0.003) and thickening fractions (right: 20 (15 to 34) %, p = 0.021, left: 24 (17 to 39) %, p = 0.002), followed by a return to pre-operative values at D3. A positive moderate correlation was found between excursion and thickening fraction (Spearman's rho 0.518 for right and 0.548 for left hemidiaphragm, p < 0.001). Interobserver reliability yielded a bias below 0.1 cm with limits of agreement (LOA) of ± 0.3 cm for excursion and - 2% with LOA of ± 21% for thickening fractions. After cardiac surgery, the evolution of diaphragmatic function is characterized by a transient impairment followed by a quick recovery. Although ultrasound diaphragmatic excursion and thickening fraction are correlated, excursion seems to be a more feasible and reproducible method in this population.

Continuous spinal anaesthesia for partial gastrectomy in an adult patient with unrepaired tetralogy of Fallot.

Correction of tetralogy of Fallot during infancy usually eliminates the risks associated with general anaesthesia. In rare cases of uncorrected defects persisting into adulthood, anaesthetic management during non-cardiac surgery may therefore be challenging. We describe the use of continuous spinal anaesthesia to successfully circumvent the operative risk of major abdominal surgery in an adult patient with uncorrected tetralogy of Fallot.

Dabigatran reversal with idarucizumab in a patient undergoing heart transplantation: first European report.

BACKGROUND: Dabigatran is a direct thrombin inhibitor with a favorable effectiveness and safety profile when compared to vitamin K antagonists, both in randomized trials and real world registries of atrial fibrillation patients. Yet, physicians' fear of high bleeding risk scenarios in daily clinical practice still precludes a more widespread use of oral anticoagulation. We hereby report a successful case of dabigatran reversal with the novel monoclonal antibody fragment idarucizumab in a patient undergoing heart transplantation. CASE PRESENTATION: A 45-year old male patient on dabigatran for atrial fibrillation thromboprophylaxis was enlisted for heart transplantation due to end-stage ischemic heart failure. Upon donor availability and suitability and following the last intake of the drug 12 h previously, activated partial thromboplastin time was measured and found to be elevated. After general anesthesia and before extracorporeal circulation, idarucizumab was administered as two boluses of 2.5 g. Orthotopic heart transplantation ensued under full heparinization and cardiopulmonary bypass. Total chest tube output was 1125 mL after 3 days and 4 units of fresh frozen plasma and one platelet pool were administered in the operating room without further need for blood products. The post-operative period was uneventful. CONCLUSIONS: Idarucizumab was associated with an effective hemostasis in the setting of heart transplantation. Dabigatran may be considered as an alternative to vitamin K antagonists in heart transplant candidates with an indication for oral anticoagulation.

Case report: acute myocarditis complicated with persistent complete heart block: a clinical dilemma when myocardial inflammation remains.

Background: Atrioventricular conduction abnormalities due to acute myocarditis are typically transient and do not require ventricular pacing beyond the acute phase of myocardial inflammation. Notwithstanding, selective injury and necrosis of the heart's conduction system may lead to persistent complete heart block (CHB) requiring device implantation. Case summary: We report the case of a 23-year-old man with acute lymphocytic myocarditis complicated by cardiogenic shock, cardiac arrest due to ventricular fibrillation, and persistent CHB. Endomyocardial biopsy (EMB) showed signs of subacute myocarditis, with no evidence of granulomas or giant cells, nor criteria for eosinophilic myocarditis. Aetiological work-up found serological evidence of previous Epstein-Barr virus (EBV) infection; Borrelia burgdorferi serology for Lyme disease was negative. The real time-polymerase chain reaction (RT-PCR) of the EMB was positive for the presence of EBV DNA, but in situ hybridization for viral ribosomal RNA (rRNA) was negative. The patient progressed favourably, and left ventricle ejection fraction recovered 2 weeks after initial presentation. However, CHB persisted for more than 3 weeks, and the patient underwent definitive pacemaker implantation with left bundle branch pacing. Discussion: Persistent CHB after acute myocarditis is generally considered unlikely, but in rare circumstances the damage portended by inflammation may be irreversible. Besides the play of chance, possible mechanisms behind the apparent predilection for the conduction system of the myocardium warrant further research.

Biventricular Takotsubo syndrome complicated with cardiogenic shock and ventricular septal rupture: a case report.

Background: Takotsubo syndrome (TTS) mimics acute coronary syndromes but can lead to serious cardiac complications, emphasizing the need for improved understanding and management. Case summary: We describe a TTS case presented with cardiogenic shock due to ventricular septal rupture (VSR). Successful treatment involved mechanical circulatory support followed by VSR surgical closure. Discussion: Ventricular septal rupture is the rarest and deadliest complication associated with TTS. Prompt recognition and a multidisciplinary approach are crucial to achieve the best possible outcome.

Spontaneous coronary artery dissection: A review for clinical and interventional cardiologists.

Spontaneous coronary artery dissection (SCAD) is an increasingly recognized cause of acute coronary syndrome, especially among young to middle-aged women with few traditional cardiovascular risk factors and low pretest probability for atherosclerotic coronary artery disease. Diagnosis by invasive coronary angiography is the gold standard and conservative therapy is generally recommended, with percutaneous or surgical revascularization being reserved for cases of clinical instability, high-risk anatomy or as bailout. Unlike atherothrombotic coronary artery disease, strong evidence on optimal medical therapy is scarce, posing unique challenges in cases of pregnancy-associated SCAD. The follow-up strategy is also of major importance, as recurrent SCAD is not infrequent, lifestyle changes and pharmacological therapy should be planned for the long term, and SCAD-associated conditions need to be addressed. This review aims to provide a practical management approach to SCAD patients for both clinical and interventional cardiologists.

Extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: a systematic review and meta-analysis of randomized clinical trials.

INTRODUCTION: Extracorporeal cardiopulmonary resuscitation (ECPR) is currently recommended as a rescue therapy for selected patients in refractory out-of-hospital cardiac arrest (OHCA). However, there is conflicting evidence regarding its effect on survival and neurological outcomes. We conducted a systematic review and meta-analysis of randomized clinical trials (RCTs) to evaluate whether ECPR is superior to standard CPR in refractory OHCA. METHODS: We performed a systematic search of electronic databases (PubMed, CENTRAL, and Scopus) until March 2023. Studies were eligible if they a) were RCTs, and b) compared ECPR vs. standard CPR for OHCA. Outcomes were defined as survival with a favorable neurological status (cerebral performance category 1 or 2) at both the shortest follow-up and at 6 months, and in-hospital mortality. Meta-analyses using a random-effects model were undertaken. RESULTS: Three RCTs, with a total of four hundred and eighteen patients, were included. Compared with standard CPR, ECPR was associated with a non-statistically significant higher rate of survival with a favorable neurological outcome at the shortest follow-up (26.4% vs. 17.2%; RR 1.47 [95% CI 0.91-2.40], P = 0.12) and at 6 months (28.3% vs. 18.6%; RR 1.48 [95% CI 0.88-2.49], P = 0.14). The mean absolute rate of in-hospital mortality was not significantly lower in the ECPR group (RR 0.89 [95% CI 0.74-1.07], P = 0.23). CONCLUSION: ECPR was not associated with a significant improvement in survival with favorable neurologic outcomes in refractory OHCA patients. Nevertheless, these results constitute the rationale for a well-conducted, large-scale RCT, aiming to clarify the effectiveness of ECPR compared to standard CPR.

Clinical outcomes in heart failure with reduced left ventricular ejection fraction and good functional capacity: The illusion of stability.

BACKGROUND: Heart failure (HF) remains a prevalent syndrome with significant morbidity and mortality. Optimal drug and device therapies are crucial to reduce the risk of death or HF admission. Yet, less symptomatic patients with good functional capacity are often perceived as having a low risk of adverse events and their attending physicians may suffer from prescription inertia or refrain from performing therapy optimization. Maximum or peak oxygen consumption (pVO2) assessed during cardiopulmonary exercise testing (CPET) is often used as a prognosis indicator and surrogate marker for functional capacity. Our goal was to assess clinical outcomes in a seemingly low risk HF population in Weber class A (pVO2>20 mL/kg/min) with reduced left ventricular ejection fraction (LVEF). METHODS: Single-center retrospective observational study enrolling consecutive HF patients with LVEF<40% (HFrEF) performing CPET between 2003 and 2018. Those with pVO2 >20 mL/kg/min were included. The primary endpoint was a composite of all-cause death or HF hospitalizations at two years after CPET. We also assessed the rates of N-terminal pro b-type natriuretic peptide (NT-proBNP) elevations at baseline. RESULTS: Seventy-two patients were included (mean age of 53±10 years; 86% male; 90% NYHA I-II; median LVEF 32%; median pVO2 24 mL/kg/min). At baseline, 93% had an NT-proBNP level >125 pg/mL (median NT-proBNP 388 [201-684] pg/mL). Overall, seven patients (10%) met the primary endpoint: three died (4%) and five (7%) had at least one HF admission. Among those who died, only one patient had an HF admission during follow up. CONCLUSION: In a clinically stable HFrEF population with good functional capacity, persistent neurohormonal activation was present in the majority, and one in ten patients died or had a HF admission at two years' follow-up. These findings support the urgent need to motivate clinicians to pursue optimal drug uptitration even in less symptomatic patients.

WITHDRAWN: Parenteral antiplatelet therapy in acute myocardial infarction complicated by cardiogenic shock - A field still needing future randomized trials?

The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.repc.2022.08.010. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Predictive value of D-dimer in the clinical outcome of severe COVID19 patients: Are we giving it too much credit?

BACKGROUND: COVID-19 is a new form of acute respiratory failure leading to multiorgan failure and ICU admission. Gathered evidence suggests that a 3-fold rise in D-dimer concentrations may be linked to poor prognosis and higher mortality. PURPOSE: To describe D-dimer admission profile in severe ICU COVID19 patients and its predictive role in outcomes and mortality. METHODS: Single-center retrospective cohort study. All adult patients admitted to ICU with COVID19 were divided into 3 groups: (1) Lower-values group (D-dimer levels < 3-fold normal range value [NRV] [500ng/mL]), Intermediate-values group (D-dimer ≥3-fold and <10-fold NRV) and Higher-value group (≥10-fold NRV). RESULTS: 118 patients (mean age 63 years, 73% males) were included (N = 73 Lower-values group, N = 31 Intermediate-values group; N = 11 Higher-values group). Mortality was not different between groups (p = 0.51). Kaplan-Meier survival curves revealed no differences (p = 0.52) between groups, nor it was verified even when gender, age, ICU length of stay, and SOFA score were considered as covariables. CONCLUSIONS: In severe COVID19 patients, the D-dimer profile does not retain a predictive value regarding patients' survivability and should not be used as a surrogate of disease severity.

Septic shock 3.0 criteria application in severe COVID-19 patients: An unattended sepsis population with high mortality risk.

BACKGROUND: Coronavirus disease 2019 (COVID-19) can be associated with life-threatening organ dysfunction due to septic shock, frequently requiring intensive care unit (ICU) admission, respiratory and vasopressor support. Therefore, clear clinical criteria are pivotal for early recognition of patients more likely to need prompt organ support. Although most patients with severe COVID-19 meet the Sepsis-3.0 criteria for septic shock, it has been increasingly recognized that hyperlactatemia is frequently absent, possibly leading to an underestimation of illness severity and mortality risk. AIM: To identify the proportion of severe COVID-19 patients with vasopressor support requirements, with and without hyperlactatemia, and describe their clinical outcomes and mortality. METHODS: We performed a single-center prospective cohort study. All adult patients admitted to the ICU with COVID-19 were included in the analysis and were further divided into three groups: Sepsis group, without both criteria; Vasoplegic Shock group, with persistent hypotension and vasopressor support without hyperlactatemia; and Septic Shock 3.0 group, with both criteria. COVID-19 was diagnosed using clinical and radiologic criteria with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive RT-PCR test. RESULTS: 118 patients (mean age 63 years, 87% males) were included in the analysis (n = 51 Sepsis group, n = 26 Vasoplegic Shock group, and n = 41 Septic Shock 3.0 group). SOFA score at ICU admission and ICU length of stay were different between the groups (P < 0.001). Mortality was significantly higher in the Vasoplegic Shock and Septic Shock 3.0 groups when compared with the Sepsis group (P < 0.001) without a significant difference between the former two groups (P = 0.713). The log rank tests of Kaplan-Meier survival curves were also different (P = 0.007). Ventilator-free days and vasopressor-free days were different between the Sepsis vs Vasoplegic Shock and Septic Shock 3.0 groups (both P < 0.001), and similar in the last two groups (P = 0.128 and P = 0.133, respectively). Logistic regression identified the maximum dose of vasopressor therapy used (AOR 1.046; 95%CI: 1.012-1.082, P = 0.008) and serum lactate level (AOR 1.542; 95%CI: 1.055-2.255, P = 0.02) as the major explanatory variables of mortality rates (R 2 0.79). CONCLUSION: In severe COVID-19 patients, the Sepsis 3.0 criteria of septic shock may exclude approximately one third of patients with a similarly high risk of a poor outcome and mortality rate, which should be equally addressed.

Coronary artery calcium scoring and cardiovascular risk reclassification in patients undergoing coronary computed tomography angiography.

INTRODUCTION: Coronary artery calcium (CAC) scoring is used for both cardiovascular risk reclassification and as a gatekeeper for coronary computed tomography angiography (CCTA). The aims of this study were to assess to what extent CAC score results can reclassify the cardiovascular risk of patients without obstructive coronary artery disease (CAD) on CCTA, and to measure the proportion of these patients whose primary prevention medication is changed after the exam. METHODS: In a retrospective analysis of a multicenter registry of individuals who underwent CCTA for suspected CAD during a two-year period, the Systematic COronary Risk Evaluation (SCORE) and Multi-Ethnic Study of Atherosclerosis (MESA) risk scores were calculated for each individual. In a subset of 184 patients, we also assessed the prescription of statins and antiplatelet agents before and after the test. RESULTS: A total of 467 patients (248 women, mean age 60±9.10 years) were included. Median CAC score was 0 (interquartile range 0-40). Overall, 249 patients (53%) and 159 (34%) were classified as being of moderate/intermediate risk according to the SCORE and MESA risk scores, respectively. Among these, 29 (12%) and 30 (19%) patients had CAC score >100 AU, making them eligible for statin therapy. The inclusion of CAC scoring in the MESA score resulted in the reclassification of 215 patients (46%). The proportion of patients who were prescribed statins or antiplatelet agents did not change significantly after the test. CONCLUSION: CAC scoring can reclassify cardiovascular risk in a significant proportion of patients undergoing CCTA. Despite this, little change was seen in the prescription of statins and antiplatelet agents.

Measuring lung water adds prognostic value in heart failure patients undergoing cardiac magnetic resonance.

To assess whether a simplified cardiac magnetic resonance (CMR)-derived lung water density (LWD) quantification predicted major events in Heart Failure (HF). Single-centre retrospective study of consecutive HF patients with left ventricular ejection fraction (LVEF) < 50% who underwent CMR. All measurements were performed on HASTE sequences in a parasagittal plane at the right midclavicular line. LWD was determined by the lung-to-liver signal ratio multiplied by 0.7. A cohort of 102 controls was used to derive the LWD upper limit of normal (21.2%). The primary endpoint was a composite of time to all-cause death or HF hospitalization. Overall, 290 patients (mean age 64 ± 12 years) were included. LWD measurements took on average 35 ± 4 s, with good inter-observer reproducibility. LWD was increased in 65 (22.4%) patients, who were more symptomatic (NYHA ≥ III 29.2 vs. 1.8%; p = 0.017) and had higher NT-proBNP levels [1973 (IQR: 809-3766) vs. 802 (IQR: 355-2157 pg/mL); p < 0.001]. During a median follow-up of 21 months, 20 patients died and 40 had ≥ 1 HF hospitalization. In multivariate analysis, NYHA (III-IV vs. I-II; HR: 2.40; 95%-CI: 1.30-4.43; p = 0.005), LVEF (HR per 1%: 0.97; 95%-CI: 0.94-0.99; p = 0.031), serum creatinine (HR per 1 mg/dL: 2.51; 95%-CI: 1.36-4.61; p = 0.003) and LWD (HR per 1%: 1.07; 95%-CI: 1.02-1.12; p = 0.007) were independent predictors of the primary endpoint. These findings were mainly driven by an association between LWD and HF hospitalization (p = 0.026). A CMR-derived LWD quantification was independently associated with an increased HF hospitalization risk in HF patients with LVEF < 50%. LWD is a simple, reproducible and straightforward measurement, with prognostic value in HF.

Cardiovascular Events After Community-Acquired Pneumonia: A Global Perspective with Systematic Review and Meta-Analysis of Observational Studies.

Acute cardiovascular disease after community-acquired pneumonia is a well-accepted complication for which definitive treatment strategies are lacking. These complications share some common features but have distinct diagnostic and treatment approaches. We therefore undertook an updated systematic review and meta-analysis of observational studies reporting the incidence of overall complications, acute coronary syndromes, new or worsening heart failure, new or worsening arrhythmias and acute stroke, as well as short-term mortality outcomes. To set a framework for future research, we further included a holistic review of the interplay between the two conditions. From 1984 to 2019, thirty-nine studies were accrued, involving 92,188 patients, divided by setting (inpatients versus outpatients) and clinical severity (low risk versus high risk). Overall cardiac complications occurred in 13.9% (95% confidence interval (CI) 9.6-18.9), acute coronary syndromes in 4.5% (95% CI 2.9-6.5), heart failure in 9.2% (95% CI 6.7-12.2), arrhythmias in 7.2% (95% CI 5.6-9.0) and stroke in 0.71% (95% CI 0.1-3.9) of pooled inpatients. During this period, meta-regression analysis suggests that the incidence of overall and individual cardiac complications is decreasing. After adjusting for confounders, cardiovascular events taking place after community-acquired pneumonia independently increase the risk for short-term mortality (range of odds-ratio: 1.39-5.49). These findings highlight the need for effective, large trial based, preventive and therapeutic interventions in this important patient population.

Cardiac intensive care in Portugal: The time for change. / Cuidados intensivos cardíacos em Portugal: projetar a mudança.

In recent years, the number of patients requiring acute cardiac care has increased, with progressively more complex cardiovascular conditions, often complicated by acute or chronic non-cardiovascular comorbidities, which affects the management and prognosis of these patients. Coronary care units have evolved into cardiac intensive care units, which provide highly specialized health care for the critical heart patient. In view of the limited human and technical resources in this area, we consider that there is an urgent need for an in-depth analysis of the organizational model for acute cardiac care, including the definition of the level of care, the composition and training of the team, and the creation of referral networks. It is also crucial to establish protocols and to adopt safe clinical practices to improve levels of quality and safety in the treatment of patients. Considering that acute cardiac care involves conditions with very different severity and prognosis, it is essential to define the level of care to be provided for each type of acute cardiovascular condition in terms of the team, available techniques and infrastructure. This will lead to improvements in the quality of care and patient prognosis, and will also enable more efficient allocation of resources.