Escalation Of Mechanical Circulatory Support Research Articles

Early Escalation of Mechanical Circulatory Support Stabilizes and Potentially Rescues Patients in Refractory Cardiogenic Shock.

Limited progress has been made in the management of cardiogenic shock (CS). Morbidity and mortality of refractory CS remain high. The effects of mechanical circulatory support (MCS) are promising, although many aspects are elusive. We evaluated efficacy and safety of early combined MCS (Impella microaxial pump + venoarterial extracorporeal membrane oxygenation [VA-ECMO]) in refractory CS and aimed to determine factors for decision-making in combined MCS. We analyzed 69 consecutive patients with refractory CS from our registry requiring combined MCS. In 12 cases, therapy was actively withdrawn according to patient's will. Patients were severely sick (Survival After Venoarterial ECMO score mean±SD, -8.9±4.4) predicting 30% in-hospital survival; ventilation 94%, dialysis 56%. Impella pumps and VA-ECMO were combined early (duration of combined MCS: median 94 hours; interquartile range, 49-150 hours). Early MCS escalation stabilized patients rapidly, reducing number and doses of catecholamines (P<0.05 versus baseline) while hemodynamics improved. Reflecting an improved microcirculation, lactate levels normalized within 24 hours (P<0.05 versus baseline). Despite refractory CS and disease severity, survival was favorable (on MCS 61%, 30 days 49%, 6 months 40%). In multivariate Cox-regression, duration of shock-to-first device (hours, hazard ratio, 1.05 [95% CI, 1.01-1.08]; P=0.007) and lactate levels after 12 hours of MCS (hazard ratio, 1.28 [95% CI, 1.09-1.51]; P=0.002) independently predicted survival. Additional right ventricular failure predisposed to futility (hazard ratio, 8.48 [95% CI, 1.85-38.91]; P=0.006). The early and consequent combination of MCS by Impella microaxial pumps and VA-ECMO enables stabilization and may rescue high-risk patients with refractory CS at low overall risk. Independent predictors of survival may guide prognostication, decision-making, and allocation of medical resources.

Mechanical Circulatory Support in Patients with Cardiogenic Shock.

To provide a contemporary concise overview of the currently available mechanical circulatory support (MCS) devices and the emerging concepts in the management of cardiogenic shock (CS). New classification of CS has emerged and is hoped to allow a unified approach to research and clinical management of CS. A number of MCS devices have also become available for clinical use in the last 2 decades. Those devices have different hemodynamic targets, provide various levels of support, and are associated with specific requirements and potential complications. Data on the utility of MCS in CS remains conflicting with randomized trials showing no benefit of MCS, and observational data suggesting an incremental value for MCS over medical therapy. However, the early use and escalation of MCS in a standardized approach do appear to provide a remarkable improvement in short-term outcomes of patients with CS. MCS devices afforded lifesaving treatment for many patients with CS. However, optimal utilization of such devices requires familiarity with their clinical data, and technical characteristics, and mandates their integration in an algorithmic team-based approach to CS.

Predictors of intra-aortic balloon pump hemodynamic failure in non-acute myocardial infarction cardiogenic shock

To characterize patient profile and hemodynamic profile of those undergoing intra-aortic balloon pump (IABP) for cardiogenic shock and define predictors of hemodynamic failure of IABP support. Clinical characteristics of IABP support in cardiogenic shock not related to acute myocardial infarction (AMI) remain poorly characterized. We retrospectively studied a cohort of 74 patients from 2010 to 2015 who underwent IABP insertion for cardiogenic shock complicating acute decompensated heart failure not due to AMI. In the overall cohort, which consisted primarily of patients with chronic systolic heart failure (89%), IABP significantly augmented cardiac index and lowered systemic vascular resistance (P<.05). Despite this improvement, 28% of these patients died (24%) or require urgent escalation in mechanical circulatory support (MCS) (4%). Multivariable regression revealed that baseline left ventricular cardiac power index (LVCPI), a measure of LV power output derived from cardiac index and mean arterial pressure (P=.01), and history of ischemic cardiomyopathy (P=.003) were significantly associated with the composite adverse-event endpoint of death or urgent MCS escalation. An IABP Failure risk score using baseline LVCPI <0.28 W/m2 and ischemic history predicted 28-day adverse events with excellent discrimination. Despite hemodynamic improvements with IABP support, patients with non-AMI cardiogenic shock still suffer poor outcomes. Patients with ischemic cardiomyopathy and low LVPCI fared significantly worse. These patients may warrant closer observation or earlier consideration of more advanced hemodynamic support.

A moribund athlete

In December, 2011, a 39-year-old woman presented to the local emergency department complaining of a 1-day history of vomiting and abdominal pain. She had had three or four episodes, with no infective prodrome. She was a physiotherapist and a competent long-distance runner; 2 days earlier she had run a 5 km race, and that morning had done her daily exercise workout. On examination there were no physical signs other than sinus tachycardia. Within 2 h, she collapsed and was moribund in acute cardiogenic shock. She was trans ferred to intensive care for mechanical ventilation and escalating inotropic support. Chest radiography showed pulmonary congestion. Trans thoracic echocardiography excluded valvular and con genital abnormalities and showed a slightly dilated, poorly functioning heart with no pericardial eff usion. Cardiac catheterisation was done to exclude coronary artery disease, and an intra-aortic balloon pump was placed for circulatory support. She had no arrhythmias. She was not pregnant and took no prescribed or recreational drugs; all infection screens were negative. She continued to deterior ate and needed two periods of chest compressions for loss of cardiac output. Acute myocarditis was suspected and she was transferred to our cardiothoracic centre for consideration of escalation of mechanical circu latory support. A consultant cardiologist and an intensivist accompanied her for the 70-mile journey, during which boluses of epinephrine were needed to maintain her circulation. She arrived 8 h after fi rst presentation, was found to be in extremis, with fi xed mottling of her trunk and limbs and hypotension despite epinephrine infusing at >1 μg/kg per min. She was anuric, profoundly acidaemic, and hypoxic on 100% oxygen (PaO2 6·1 kPa, pH 6·9, lactate 16 mmol/L, base excess –13). She was taken directly to theatre for median sternotomy. The heart was tense and dilated and a myocardial biopsy sample was taken from the left ventricle. Central veno-arterial extracorporeal membrane oxygenation (ECMO) was established; a cannula was inserted via the abdominal wall into the right atrium to drain systemic venous blood into the ECMO pump, which returned oxygenated blood via a separate cannula into the ascending aorta (fi gure). This procedure restored systemic cardiac output, and the sternum was closed. Her condition rapidly improved and the inotropes were stopped. During the next 24 h, signifi cant hypertension developed. The biopsy sample showed no evidence of myocarditis but did suggest catecholamine-induced myocyte damage. Continuing resistant hypertension raised the possibility of a catecholamine-secreting tumour. CT of the abdomen showed a large left adrenal mass (5×6 cm). Left adrenal ectomy was done (day 3) with concurrent ECMO support. Subsequent echo cardiography showed recovering biven tricular function (day 5) and ECMO was discontinued. She recovered fully, and was discharged in February, 2012. Histology confi rmed a benign phaeochromocytoma. Phaeochromocytomas are rare catecholamine-secreting tumours of the chromaffi n cells of the adrenal gland. They have diverse presentations including vomiting and abdominal pain, hypertension, as well as sweating, headache, and palpitations, which are typically episodic. Most cases are insidious, and although catecholamine-induced cardiomyopathy is well recognised, such a fulminant presen tation is rare. In our patient’s case, timely referral, and escalation of mechanical circulatory support were essential for resuscitation and diagnosis. Without special ised anaesthetic work-up before the adren alectomy, ECMO enabled control of the circulation during this operation. There were several support options for our patient but central ECMO could be established exped itiously and allowed examination and biopsy of the heart. Physicians should consider central ECMO in such cases as the mech an ical circulatory support of choice for “bridge to diagnosis”.