Sumaya Hammami

Cardiac output determination using a widely available direct continuous oxygen consumption measuring device: a practical way to get back to the gold standard

BACKGROUNDnAccurate assessment of cardiac output (CO) is essential for the hemodynamic assessment of valvular heart disease. Estimation of oxygen consumption (VO2) and thermodilution (TD) are employed in many cardiac catheterization laboratories (CCL) given the historically cumbersome nature of direct continuous VO2 measurement, the gold standard for this technique. A portable facemask device simplifies the direct continuous measurement of VO2, allowing for relatively rapid and continuous assessment of CO.nnnMETHODS AND MATERIALSnThirty consecutive patients undergoing right heart catheterization had simultaneous determination of CO by both direct continuous and assumed VO2 and TD. Assessments were only made when a plateau of VO2 had occurred. All measurements of direct continuous and assumed VO2, as well as, TD CO were obtained in triplicate.nnnRESULTSnDirect continuous VO2 CO and assumed VO2 CO correlated poorly (R=0.57; ICC=0.59). Direct continuous VO2 CO and TD CO also correlated poorly (R=0.51; ICC=0.60). Repeated direct continuous VO2 CO measurements were extremely correlated and reproducible [(R=0.93; ICC=0.96) suggesting that this was the most reliable measurement of CO.nnnCONCLUSIONSnCO calculated from direct continuous VO2 measurement varies substantially from both assumed VO2 and TD based CO, which are widely used in most CCL. These differences may significantly impact the CO measurements. Furthermore, continuous, rather than average, measurement of VO2 appears to give highly reproducible results.

Impact of a Multidisciplinary Team Approach Including an Intensivist on the Outcomes of Critically Ill Patients in the Cardiac Care Unit

OBJECTIVEnTo investigate the impact of integrating a medical intensivist into a cardiac care unit (CCU) multidisciplinary team on the outcomes of CCU patients.nnnPATIENTS AND METHODSnWe conducted a retrospective cohort study of 2239 CCU admissions between July 1, 2011, and July 1, 2013, which constituted patients admitted in the 12 months before and 12 months after the introduction of intensivists into the CCU multidisciplinary team. This team included a cardiologist, a medical intensivist, medical house staff, nurses, a pharmacist, a dietitian, and physical and respiratory therapists. The primary outcome was CCU mortality. Secondary outcomes included hospital mortality, CCU length of stay, hospital length of stay, and duration of mechanical ventilation.nnnRESULTSnAfter the implementation of a multidisciplinary team approach, there was a significant decrease in both adjusted CCU mortality (3.5% vs 5.9%; P=.01) and hospital mortality (4.4% vs 11.1%; P<.01). A similar impact was observed on adjusted mean CCU length of stay (2.5±2.0 vs 2.9±2.0 days; P<.01), adjusted mean hospital length of stay (7.0±4.5 vs 7.5±4.5 days; P<.01), and adjusted mean ventilation duration (2.0±1.0 vs 4.3±2.5 days; P<.01).nnnCONCLUSIONnThe implementation of a multidisciplinary team approach in which an intensivist and a cardiologist comanage the critical care of CCU patients is feasible and may result in better patient outcomes.

THE IMPACT OF TRANSAORTIC GRADIENT AND TRANSAORTIC FLOW ON THE DISCREPANCY BETWEEN ECHOCARDIOGRAPHIC AND CARDIAC CATHETERIZATION EVALUATION OF SEVERE AORTIC STENOSIS WITH PRESERVED EJECTION FRACTION

Background: Current guidelines discourage aortic stenosis (AS) evaluation by direct pressure measurement if echocardiography (echo) is adequate. However several studies show sizable discrepancies between echo and catheterization (cath) lab measurements. We wanted to investigate the impact of both

SAFETY AND EFFICACY OF USING PRESSURE WIRE WITH DOBUTAMIN INFUSION IN THEMOYNAMIC ASSESSMENT OF LOW FLOW LOW GRADIENT AORTIC STENOSIS

Background: Current guidelines discourage aortic stenosis (AS) evaluation by direct pressure measurement if echocardiography (echo) is adequate. However several studies show sizable differences between echo and catheterization (cath) lab measurements. Dobutamine Challenge is recommended for

Safety and utility of dobutamine and pressure wire use in the hemodynamic assessment of low-flow, low-gradient aortic stenosis with reduced left ventricular ejection fraction

BACKGROUNDnThe ACC/AHA guidelines recommend low-dose dobutamine challenge for hemodynamic assessment of the severity of AS in patients with low flow, low gradient aortic stenosis with reduced ejection fraction (EF) (LFLG-AS; stage D2). Inherent pitfalls of echocardiography could result in inaccurate aortic valve areas (AVA), which have downstream prognostic implications. Data on the safety and efficacy of coronary pressure wire and fluid-filled catheter use for low dose dobutamine infusion is sparse.nnnMETHODSnWe retrospectively analyzed 39 consecutive patients with EF<50%, AVA<1cm2 and SVI<35ml/m2 on echocardiography who underwent simultaneous right and left heart catheterization. Hemodynamic assessments were performed at baseline and at every increment in the dobutamine infusion rate (The infusion was continued until maximal dose of dobutamine or a mean AV gradient>40mmHg was attained. The occurrence of sustained ventricular arrhythmias, symptomatic hypotension or intolerable symptoms leading to cessation of infusion was recorded. Transient ischemic attacks (TIAs) or clinically apparent strokes periprocedurally or up to 30days after the procedure were recorded.nnnRESULTSnDobutamine challenge confirmed true AS in 26 patients (67%) and pseudosevere AS in 34%. No sustained arrhythmias, hypotension or cessation of infusion from intolerable symptoms were observed. No clinical strokes or TIAs were observed up to 30days after procedure in any of these patients.nnnCONCLUSIONSnHemodynamic assessment of AS using a pressure wire with dobutamine challenge is a safe and effective tool in identifying truly severe AS in patients with LFLG-AS with reduced EF.

POTENTIAL BENEFIT OF USING PRESSURE WIRE IN HEMODYNAMIC ASSESSMENT OF PARADOXICAL LOW FLOW, LOW GRADIENT SEVERE AORTIC STENOSIS WITH PRESERVED EJECTION FRACTION

Current guidelines discourage aortic stenosis (AS) evaluation by direct pressure measurement if echocardiography is adequate due to potential stroke risk reported in old studies. Patients with both low gradient (Gradient < 40 mm HG) and/or flow (Stroke Volume Index SVI < 35) with normal ejection

PARADOXICAL LOW FLOW LOW GRADIENT SEVERE AORTIC STENOSIS WITH PRESERVED LEFT VENTRICULAR EJECTION FRACTION: IMPACT OF SURGERY VERSUS MEDICAL THERAPY

Combining transaortic flow and gradient defined four different aortic stenosis (AS) subgroups [normal flow, high gradient [NF/HG]; normal flow, low gradient [NF/LG]; low flow, high gradient [LF/HG] and low flow, low gradient [LF/LG]). The natural history and need for aortic valve replacement (AVR)

CRT-500.11 Misclassification of Pulmonary Hypertension Due to Reliance on Pulmonary Capillary Wedge Pressure or Left Ventricular End-Diastolic Pressure Instead of Direct Mean Left Atrial Pressure

Pulmonary arterial hypertension (PAH) is typically distinguished from pulmonary venous hypertension (PVH) by documenting a pulmonary capillary wedge pressure (PCWP) < 15 mm Hg. However, PCWP has uncertain utility in establishing PAH. Other suggests using left ventricular end-diastolic pressure (