Precardiogenic Shock: A New Clinical Entity

Istaroxime for Patients with Acute Heart Failure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Istaroxime, an intravenous inotropic agent with a dual mechanism-increasing both cardiomyocyte contractility and relaxation-is a novel treatment for acute heart failure (AHF), the leading cause of morbidity and mortality in heart failure. We conducted a systematic review and meta-analysis that synthesized randomized controlled trials (RCTs), which were retrieved by systematically searching PubMed, Web of Science, SCOPUS, and Cochrane until 24 April 2023. We used a fixed-effect or random-effect model-according to heterogeneity-to pool dichotomous data using the risk ratio (RR) and continuous data using the mean difference (MD), with a 95% confidence interval (CI). We included three RCTs with a total of 300 patients. Istaroxime was significantly associated with an increased left ventricular ejection fraction (mL) (MD: 1.06, 95% CI: 0.29, 1.82; p = 0.007), stroke volume index (MD: 3.04, 95% CI: 2.41, 3.67; p = 0.00001), and cardiac index (L/min/m2) (MD: 0.18, 95% CI: 0.11, 025; p = 0.00001). Also, istaroxime was significantly associated with a decreased E/A ratio (MD: -0.39, 95% CI: -0.58, -0.19; p = 0.0001) and pulmonary artery systolic pressure (mmHg) (MD: 2.30, 95% CI: 3.20, 1.40; p = 0.00001). Istaroxime was significantly associated with increased systolic blood pressure (mmHg) (MD: 5.32, 95% CI: 2.28, 8.37; p = 0.0006) and decreased heart rate (bpm) (MD: -3.05, 95% CI: -5.27, -0.82; p = 0.007). Since istaroxime improved hemodynamic and echocardiographic parameters, it constitutes a promising strategy for AHF management. However, the current literature is limited to a small number of RCTs, warranting further large-scale phase III trials before clinical endorsement.

Safety and Efficacy of Istaroxime 1.0 and 1.5 µg/kg/min for Patients With Pre-Cardiogenic Shock

INTRODUCTION

Istaroxime was shown, in a small study, to increase systolic blood pressure (SBP) in patients with pre-cardiogenic shock (CS) due to acute heart failure (AHF).

OBJECTIVES

In the current analysis, we describe the effects of 2 doses of istaroxime 1.0 (Ista-1) and 1.5 µg/kg/min (Ista-1.5).

METHODS

The target dose of istaroxime, administered in a double-blind, placebo-controlled fashion, was 1.5 µg/kg/min in the first cohort (n = 24), and it was reduced to 1.0 µg/kg/min in subsequent patients (n = 36).

RESULTS

Ista-1 was associated with numerically larger effects on SBP area under the curve, with a 93.6% relative increase from baseline during the first 6 hours with Ista-1 vs 39.5% for Ista-1.5, and with a 49.4% and 24.3% relative increase, respectively, at 24 hours. Compared to placebo, Ista-1.5 had more worsening HF events until day 5 and fewer days alive out of hospital (DAOH) through day 30. Ista-1 had no worsening HF events, and DAOH to day 30 were significantly increased. Effects on echocardiographic measures were similar, although decreases in left ventricular end systolic and diastolic volumes were numerically larger in the Ista-1 group. Ista-1, but not Ista-1.5, showed numerically smaller creatinine increases and larger decreases in natriuretic peptides as compared to placebo. There were 5 serious adverse events in Ista-1.5 (4 of which were cardiac) but only 1 in Ista-1.

CONCLUSIONS

In patients with pre-CS due to AHF, istaroxime 1.0 µg/kg/min induced beneficial effects on SBP and DAOH. Clinical benefits appear to be reached at dosages less than 1.5 ug/kg/min.

Early Mechanical Circulatory Support for Cardiogenic Shock

Reversal of cardiogenic shock depends on its early recognition and prompt initiation of therapy. Recognition of the clinical and hemodynamic deterioration that precedes cardiogenic shock is a crucial step in its early detection. Treatment of pre-cardiogenic shock is chiefly pharmacologic with intravenous administration of pressor, inotropic, and loop diuretic agents. Failure to reverse the preshock state with pharmacotherapy entails progression to cardiogenic shock and the need for prompt mechanical circulatory support with membrane oxygenation and possibly left ventricular decompression.

Safety and efficacy of istaroxime in patients with acute heart failure-related pre-cardiogenic shock - a multicentre, randomized, double-blind, placebo-controlled, parallel group study (SEISMiC)

AIMS

We examined the effects of istaroxime in patients hospitalized for acute heart failure (AHF) related Society for Cardiovascular Angiography and Interventions (SCAI) stage B pre-cardiogenic shock (CS).

METHODS AND RESULTS

Sixty patients with AHF without acute myocardial infarction with pre-CS, defined as systolic blood pressure (SBP) <90 mmHg without hypoperfusion, venous lactate ≥2 mmol/L and/or mechanical or inotropic support, were randomized to istaroxime 1.0-1.5 μg/kg/min or placebo for 24 h. The primary endpoint, the adjusted area under the curve (AUC) change in SBP from time of treatment to 6 h, was 53.1 (standard error [SE] 6.88) mmHg × hour versus 30.9 (SE 6.76) mmHg × hour with istaroxime versus placebo (p = 0.017). Adjusted SBP AUC at 24 h was 291.2 (SE 27.5) versus 208.7 (SE 27.0) mmHg × hour (p = 0.025). At 24 h, some echocardiographic measurements improved with istaroxime versus placebo including cardiac index (+0.21 L/min/m² ; p = 0.016), left atrial area (-1.8 cm² ; p = 0.008), and left ventricular end-systolic volume (-12.0 ml; p = 0.034). There were no significant differences in pulse pressure, laboratory measurements, serious adverse events or adverse events between the treatment groups except for more nausea, vomiting and infusion site pain in the istaroxime-treated patients. In a post-hoc analysis, patients receiving ≤1.0 μg/kg/min versus 1.5 μg/kg/min had similar increase in blood pressure, but a trend towards less adverse events.

CONCLUSION

In a phase 2a study of patients with AHF related pre-CS, istaroxime improved blood pressure and some echocardiography measures related to heart failure and was well tolerated.

Defining Shock and Preshock for Mortality Risk Stratification in Cardiac Intensive Care Unit Patients

BACKGROUND

Previous studies have defined preshock as isolated hypotension or isolated hypoperfusion, whereas shock has been variably defined as hypoperfusion with or without hypotension. We aimed to evaluate the mortality risk associated with hypotension and hypoperfusion at the time of admission in a cardiac intensive care unit population.

METHODS

We analyzed Mayo Clinic cardiac intensive care unit patients admitted between 2007 and 2015. Hypotension was defined as systolic blood pressure <90 mm Hg or mean arterial pressure <60 mm Hg, and hypoperfusion as admission lactate >2 mmol/L, oliguria, or rising creatinine. Associations between hypotension and hypoperfusion with hospital mortality were estimated using multivariable logistic regression.

RESULTS

Among 10 004 patients with a median age of 69 years, 43.1% had acute coronary syndrome, and 46.1% had heart failure. Isolated hypotension was present in 16.7%, isolated hypoperfusion in 15.3%, and 8.7% had both hypotension and hypoperfusion. Stepwise increases in hospital mortality were observed with hypotension and hypoperfusion compared with neither hypotension nor hypoperfusion (3.3%; all P<0.001): isolated hypotension, 9.3% (adjusted odds ratio, 1.7 [95% CI, 1.4-2.2]); isolated hypoperfusion, 17.2% (adjusted odds ratio, 2.3 [95% CI, 1.9-3.0]); both hypotension and hypoperfusion, 33.8% (adjusted odds ratio, 2.8 [95% CI, 2.1-3.6]). Adjusted hospital mortality in patients with isolated hypoperfusion was higher than in patients with isolated hypotension (P=0.02) and not significant different from patients with both hypotension and hypoperfusion (P=0.18).

CONCLUSIONS

Hypotension and hypoperfusion are both associated with increased mortality in cardiac intensive care unit patients. Hospital mortality is higher with isolated hypoperfusion or concomitant hypotension and hypoperfusion (classic shock). We contend that preshock should refer to isolated hypotension without hypoperfusion, while patients with hypoperfusion can be considered to have shock, irrespective of blood pressure.