Epidemiology of Sudden Cardiac Death in Patients with Heart Failure

Correlation between the warning symptoms and prognosis of cardiac arrest

BACKGROUND

A low survival rate in patients with cardiac arrest is associated with failure to recognize the condition in its initial stage. Therefore, recognizing the warning symptoms of cardiac arrest in the early stage may play an important role in survival.

AIM

To investigate the warning symptoms of cardiac arrest and to determine the correlation between the symptoms and outcomes.

METHODS

We included all adult patients with all-cause cardiac arrest who visited Peking University Third Hospital or Beijing Friendship Hospital between January 2012 and December 2014. Data on population, symptoms, resuscitation parameters, and outcomes were analysed.

RESULTS

Of the 1021 patients in the study, 65.9% had symptoms that presented before cardiac arrest, 25.2% achieved restoration of spontaneous circulation (ROSC), and 7.2% survived to discharge. The patients with symptoms had higher rates of an initial shockable rhythm (12.2% vs 7.5%, P = 0.020), ROSC (29.1% vs 17.5%, P = 0.001) and survival (9.2% vs 2.6%, P = 0.001) than patients without symptoms. Compared with the out-of-hospital cardiac arrest (OHCA) without symptoms subgroup, the OHCA with symptoms subgroup had a higher rate of calls before arrest (81.6% vs 0.0%, P < 0.001), health care provider-witnessed arrest (13.0% vs 1.4%, P = 0.001) and bystander cardiopulmonary resuscitation (15.5% vs 4.9%, P = 0.002); a shorter no flow time (11.7% vs 2.8%, P = 0.002); and a higher ROSC rate (23.8% vs 13.2%, P = 0.011). Compared to the in-hospital cardiac arrest (IHCA) without symptoms subgroup, the IHCA with symptoms subgroup had a higher mean age (66.2 ± 15.2 vs 62.5 ± 16.3 years, P = 0.005), ROSC (32.0% vs 20.6%, P = 0.003), and survival rates (10.6% vs 2.5%, P < 0.001). The top five warning symptoms were dyspnea (48.7%), chest pain (18.3%), unconsciousness (15.2%), paralysis (4.3%), and vomiting (4.0%). Chest pain (20.9% vs 12.7%, P = 0.011), cardiac etiology (44.3% vs 1.5%, P < 0.001) and survival (33.9% vs 16.7%, P = 0.001) were more common in males, whereas dyspnea (54.9% vs 45.9%, P = 0.029) and a non-cardiac etiology (53.3% vs 41.7%, P = 0.003) were more common in females.

CONCLUSION

Most patients had warning symptoms before cardiac arrest. Dyspnea, chest pain, and unconsciousness were the most common symptoms. Immediately recognizing these symptoms and activating the emergency medical system prevents resuscitation delay and improves the survival rate of OHCA patients in China.

Hyperkalemia and Renin-Angiotensin-Aldosterone System Inhibitors Dose Therapy in Heart Failure With Reduced Ejection Fraction

Renin-angiotensin-aldosterone system inhibitors (RAASi) are known to improve outcomes in patients who have heart failure with reduced ejection fraction (HFrEF). To reduce mortality in these patients, RAASi should be uptitrated to the maximally tolerated dose. However, RAASi may also cause hyperkalemia. As a result of this side-effect, doses of RAASi are reduced, discontinued and seldom reinstated. Thus, the therapeutic target needed in these patients is often not reached because of hyperkalemia. Also, submaximal dosing of RAASi may be a result of symptomatic hypotension, syncope, hypoperfusion, reduced kidney function and other factors. The reduction of RAASi dose leads to adverse outcomes, such as an increased risk of mortality. Management of these side-effects is pivotal to maximise the use of RAASi in HFrEF, particularly in high-risk patients.

A Review of Prognostic Tools in Heart Failure

A minority of patients with end-stage disease are referred to palliative medicine for consultation in advanced heart failure. Educating stakeholders, including primary care, cardiology, and critical care of the benefits of hospice and palliative medicine for patients with poor prognosis, may increase appropriately timed referrals and improve quality of life for these patients. This article reviews multiple tools useful in prognostication in the setting of advanced heart failure.

Most Heart Failure Patients Die from Pump Failure: Implications for Therapy

Careful review of the literature of the last 20 years since the appearance of the first positive trials in heart failure indicates an evolution in the mode of death moving from sudden death to a predominance of pump failure death (i.e., death due to progression of heart failure). Pump failure is becoming a leading cause of mortality in a range of patient profiles, including patients with newly diagnosed or severe heart failure, patients with devices, and patients with heart failure associated with Chagas' disease. Indeed, the evidence suggests that modern management strategies, such as beta-blockers and devices, are successful in preventing sudden death. However, this means that optimally treated patients are at greater risk for the consequences of pump failure (death, hospitalization, and reduced quality of life). This highlights a new important unmet need in heart failure, and a priority for current research should be therapies that reduce pump failure death and hospitalization for more cost-effective management of the disease. Insofar as one-third of heart failure patients do not survive more than 3 years after diagnosis, properly addressing pump failure is an essential target in heart failure.