The clinical profile of patients with suspected cardiogenic shock due to predominant left ventricular failure: a report from the SHOCK Trial Registry

OBJECTIVES We sought to evaluate the frequency of pulmonary congestion and associated clinical and hemodynamic findings in patients with suspected cardiogenic shock (CS). BACKGROUND The prevalence of pulmonary congestion in the setting of CS is uncertain. METHODS The 571 SHOCK Trial Registry patients with predominant left ventricular failure (LVF) were divided into four groups: Group A = no pulmonary congestion/no hypoperfusion = 14 (3%), Group B = isolated pulmonary congestion = 32 (6%), Group C = isolated hypoperfusion = 158 (28%) and Group D = congestion with hypoperfusion = 367 (64%). Statistical comparisons between Group C and D only, with regard to patient demographics, hemodynamics, treatment and outcome, were made. RESULTS A significant proportion of patients with shock had no pulmonary congestion (Group C = 28%, 95% CI, 24% to 31%). Age and gender in this group were similar to Group D. Group C patients were less likely to have a prior MI (p = 0.028), congestive heart failure (p = 0.005) and renal insufficiency (p = 0.032), and the index MI was less likely to be anterior (p = 0.044). Cardiac output, cardiac index and ejection fraction were similar for the two groups but pulmonary capillary wedge pressure was slightly lower for Group C (22 vs. 24 mm Hg, p = 0.012). Treatment with thrombolysis, angioplasty and bypass surgery was similar in the two groups. In-hospital mortality rates for Groups C and D were 70% and 60%, respectively (p = 0.036). After adjustment, this difference was no longer statistically significant (p = 0.153). CONCLUSIONS Absence of pulmonary congestion at initial clinical evaluation does not exclude a diagnosis of CS due to predominant LVF and is not associated with a better prognosis.