TOP TEN SELECTED PAPERS - May 2009

1

Kardiol Pol. 2009 May;67(5):496-503.

Value of intraoperative transoesophageal echocardiography in monitoring left
ventricular function in patients undergoing elective coronary artery bypass
grafting.

Winter M, Sobkowicz B, Zajac B, Cichon R.

Dolnoslaskie Centrum Chorób Serca "Medinet", ul. Kamienskiego 73 a, 51-124
Wroclaw, tel.: +48 71 320 94 01, fax: +48 71 320 94 00, e-mail:
winter@medinet.pl.

Background: Intraoperative transoesophageal echocardiography (IOTEE) is an
integral part of many cardiac surgical procedures and is employed during major
non-cardiac operations to monitor cardiac performance, particularly in high-risk 
patients. In the case of elective coronary artery bypass grafting (CABG)
procedures this examination is performed according to experience and availability
in a given centre. Aim: To evaluate the value of IOTEE in monitoring left
ventricular (LV) function in patients undergoing elective CABG with the use of
cardiopulmonary bypass (CPB). Methods: In fifty five patients (mean 66 +/- 9
years), mean EuroSCORE: 4.5 +/- 2.9 scheduled for elective CABG in CPB, IOTEE was
performed after induction of anaesthesia, 5 and 30 min after weaning from CPB.
Intraoperative parameters of LV function and volume (EDV/BSA) were compared with 
the data obtained by transthoracic echocardiography (TTE) performed before and 30
days after surgery. Results: Significant depression of LV ejection fraction
(LVEF) was found after induction of aesthesia (decline from 52.2 +/- 11.2% to
49.8 +/- 11.5%, p = 0.003). Subsequent improvement of LVEF was noticed at 1-month
follow-up (p = 0.01). The highest wall motion score index (WMSI) (1.5 +/- 0.43)
was found after weaning from CPB, the lowest at follow-up (1.36 +/- 0.4). Change 
of EF and WMSI at each stage of examination was significant (p < 0.001).
Significant decrease of EDV/BSA was found 30 min after weaning from CPB (decline 
from 53.5 +/- 23.2 to 49.1 +/- 21.9 ml/m2, p = 0.05). Significant depression of
EF 5 min after weaning from CPB was detected only in patients with CPB time
longer than 120 min (decline of 4.2%, p = 0.001). Conclusion: Intraoperative
transoesophageal echocordiography during elective CABG allows one to control
difficult stages of the surgical procedure and to select patients at risk of
perioperative haemodynamic deterioration. Our study supports the routine
application of IOTEE in elective CABG.

J Card Surg. 2009 May 28. [Epub ahead of print]

Right Anterior Minithoracotomy for Minimal Access Aortic Valve Replacement.

Weber A, Reser D, Reuthebuch O, Syburra T, Seifert B, Plass A, Genoni M,
Grünenfelder J, Tavakoli R.

Department of Cardiovascular Surgery, University Hospital Zurich, Zurich,
Switzerland.

Abstract Background: Controversy surrounds the safety of the use of minimal
access aortic valve replacement (AVR). Most studies report on partial sternotomy 
as the preferred approach. Here we report our experience with a homogenous series
of patients undergoing AVR through a right minithoracotomy (MAVR). Methods:
Preoperative 64-multislice computer-tomography (64-MSCT) was done to optimize the
approach in MAVR patients. One hundred and sixteen patients underwent MAVR by a
standardized technique. Results: Guided by 64-MSCT, the second intercostal space 
was entered in 16 and the third in 100 patients. Anatomical contraindications to 
this technique were further defined by 64-MSCT: distance from intercostal space
to aortic valve >/=12 cm and to aortic cannulation site >/=10 cm, aortic annulus 
diameter 

J Card Surg. 2009 May 15. [Epub ahead of print]

Nesiritide Enhances Myocardial Protection during the Revascularization of Acutely
Ischemic Myocardium.

Lazar HL, Bao Y, Siwik D, Frame J, Mateo CS, Colucci WS.

Department of Cardiothoracic Surgery, Boston Medical Center, and the Boston
University School of Medicine, Boston, MA.

Abstract Background: Nesiritide, a recombinant human B-type natriuretic peptide, 
has been used in conjunction with inotropic agents in the management of low
cardiac output and pulmonary hypertension following cardiac surgery. However, its
independent effects on intraoperative myocardial protection are unknown. This
study was, therefore, undertaken to determine whether nesiritide alone could
enhance myocardial protection when given intraoperatively in a porcine model
simulating urgent coronary artery bypass graft surgery. Methods and Results:
Twenty pigs underwent occlusion of the second and third diagonal coronary
arteries using snares for 90 minutes followed by 45 minutes of antegrade, cold
blood cardioplegic arrest and 180 minutes of reperfusion on cardiopulmonary
bypass during which the snares were released. Ten animals received an IV bolus of
Nesiritide (2 mug per kg) at the initiation of coronary occlusion followed by a
0.01-mug/kg per min IV infusion during coronary occlusion, cardioplegic arrest,
and reperfusion. Ten other animals underwent the same protocol without Nesiritide
(placebo). Infarct size was assessed by the area of necrosis/area of risk using
histochemical staining, endothelial function by the % change in coronary
vasodilation using ring chamber methodology, and lung edema using % change in
wet/dry weights. Nesiritide-treated animals had significantly decreased infarct
size (23.44% 3.13 SD% vs. 37.95%+/- 1.05%; p < 0.003), better preservation of
endothelial function (70.1%+/- 12.3% vs. 38.9%+/- 10.3%; p < 0.001), and less
lung edema (3.39%+/- 2.13% vs. 4.72 +/- 1.14%; p = 0.23). Conclusions: In a
porcine model of acute coronary occlusion simulating urgent CABG surgery, the
intraoperative infusion of nesiritide limits myocardial injury. 

Eur J Cardiothorac Surg. 2009 May 29. [Epub ahead of print]

Evaluation of continuous veno-venous hemofiltration for the treatment of
cardiogenic shock in conjunction with acute renal failure after cardiac surgery.

Vidal S, Richebé P, Barandon L, Calderon J, Tafer N, Pouquet O, Fournet N,
Janvier G.

Department of Anesthesia and Intensive Care II, Professor Gérard Janvier,
Cardiologic Hospital of Haut-Lévêque, University Hospital of Bordeaux, Avenue de 
Magellan, 33604 Pessac, France(1).

Background: Cardiogenic dysfunction with acute renal failure (ARF) and diuretic
drug resistance increases mortality after cardiac surgery with cardiopulmonary
bypass (CPB) in adults. Until few years ago, intermittent renal replacement
therapy (IRRT) was the only therapeutical strategy proposed to such patients. Few
data are available in the literature regarding the use of continuous veno-venous 
haemofiltration (CVVH) in this clinical context. The aim of our observational
study was to evaluate the impact of CVVH strategy on ARF in conjunction with
cardiogenic shock after cardiac surgery and on its well-known associated poor
outcome. Methods: During the period 2005-2006, we prospectively collected data
from our database as we controlled the renal replacement therapy using CVVH
(n=73). We also retrospectively collected data from our computerised database on 
patients who were treated with IRRT (n=68, period 2002-2003). Among CVVH-treated 
patients, a multivariate analysis of the data aimed to identify risk factors
associated with 30-day mortality. Results: In patients who presented with ARF in 
conjunction with cardiogenic shock after cardiac surgery, 30-day mortality rate
was 59% for the IRRT group and 42% for the CVVH group. Within the CVVH group, the
logistic regression and multivariate analyses reported that some variables were
associated with higher mortality risk: a score F concerning the urinary output
criteria of the RIFLE (risk, injury, failure, loss, end-stage kidney disease)
classification (for scores R or I: odds ratio (OR): 0.01, 95% confidence interval
(95% CI): 0.02-0.59; p=0.01), plasma bilirubin (OR: 1.44, 95% CI: 1.12-1.84;
p=0.04), total CVVH duration <50h over 72h (>50h; OR: 0.009, 95% CI: 0.04-0.93;
p=0.01), the need of catecholamine support (OR: 12.88, 95% CI: 1.95-84.96;
p=0.01), tachycardia in the intensive care unit (ICU; OR: 1.64, 95% CI:
1.02-2.65; p=0.04), surgery duration (<300min; OR: 0.11, 95% CI: 0.02-0.71;
p=0.02) and combined cardiac surgery (OR: 7.00, 95% CI: 1.29-37.88; p=0.02).
Conclusion: In patients with ARF in conjunction with cardiogenic shock after
cardiac surgery, renal replacement therapeutic strategy based on long-lasting
CVVH could improve patients' outcome. The identification of risk factors
associated with a poor outcome would help to better manage such patients in the
ICU. Low total duration of CVVH within the first 72h was one criteria related to 
poor outcome. This suggests that CVVH must be initiated as soon as possible when 
ARF with diuretic resistance occurs in patients after cardiac surgery and
continued as long as possible for the first 3 days.

Pediatr Crit Care Med. 2009 May 15. [Epub ahead of print]

Adrenocortical response in infants undergoing cardiac surgery with
cardiopulmonary bypass and circulatory arrest.

Gajarski RJ, Stefanelli CB, Graziano JN, Kaciroti N, Charpie JR, Vazquez D.

From the Department of Pediatrics, Divisions of Cardiology (RJG, CBS, JNG, JRC)
and Endocrinology (DV); and Center for Growth and Development (NK, DV),
University of Michigan Health Center, Ann Arbor, MI.

OBJECTIVE:: To detail changes in adrenocorticotropic hormone (ACTH), cortisol,
and aldosterone levels following cardiac surgery and to test the hypothesis that 
postcardiotomy infants requiring excessively high-dose vasopressor support will
demonstrate adrenal insufficiency which will be proportional to cardiopulmonary
bypass (CPB)/circulatory arrest times and vasopressor requirements. DESIGN::
Prospective observational pilot study. SETTING:: A tertiary care pediatric
cardiac intensive care unit. PATIENTS:: Prospectively enrolled infants were
divided into three subgroups: CPB, CPB with deep hypothermic circulatory arrest
(DHCA), and control subjects. INTERVENTIONS:: None. MEASUREMENTS AND MAIN
RESULTS:: A representative patient sample from each surgical group underwent
preoperative synthetic ACTH testing. Postoperative serum samples for cortisol,
ACTH, and inotrope score (IS) were collected at discrete intervals x48 hours
along with patient demographics, surgical procedure, and CPB/DHCA times.
Fifty-eight patients comprised 31 CPB, 22 DHCA, and 5 controls. Ten patients with
DHCA, analyzed separately, received intraoperative steroids. Tested patients
demonstrated preoperative adrenal competence. Cortisol peaked within 2 hours of
surgery without differences among groups. ACTH inversely correlated with bypass
time in patients with DHCA (p = 0.03) but not with circulatory arrest time. Peak 
cortisol level did not correlate with simultaneous IS. Although not noted in any 
DHCA-steroid patients, nine patients had increased ACTH/cortisol ratios in
association with elevated ISs suggesting inadequate adrenal responsiveness to
endogenous ACTH. CONCLUSIONS:: The majority of infants with congenital heart
disease and intact hypothalamic-pituitary-adrenal axes demonstrated an
appropriate adrenocortical stress response to cardiac surgery. Peak serum
cortisol was unrelated to CPB/DHCA time and did not predict the level of inotrope
support. However, a subset of patients with elevated ACTH/cortisol ratios seemed 
to have a clinical status consistent with adrenal insufficiency and may be a
target group for early postoperative steroid therapy.

J Cardiovasc Med (Hagerstown). 2009 May;10(5):383-93.

Transcatheter aortic valve implantation in the operating room: early experience.

Fusari M, Alamanni F, Bona V, Muratori M, Salvi L, Parolari A, Biglioli P.

Department of Cardiovascular Surgery, Centro Cardiologico Monzino IRCCS, Milan,
Italy.

OBJECTIVE: Aortic stenosis is the most common valvular heart disease in the
Western world and the proportion of patients unsuitable for conventional surgery 
is increasing as a result of aging and comorbidities. We report our early
experience with transcatheter aortic valve implantation in high-risk patients
with severe symptomatic aortic stenosis. METHODS: Transcatheter Edwards-SAPIEN
valve implantation was attempted in 22 patients (80 +/- 5 years) in whom surgical
risk was deemed excessive because of older age, poor left ventricular function,
comorbidities, or all. A retrograde transarterial approach was used in 15 cases. 
In seven cases, valve implantation was performed by transapical approach because 
of aortic or iliac artery tortuosity, or both, and stenosis. All procedures were 
performed without cardiopulmonary bypass. Rapid ventricular pacing was used to
reduce cardiac output while delivering balloon-expandable prosthesis. RESULTS:
One patient died because of aortic dissection during early catheterization
maneuvers. In the remaining patients, procedural success was achieved in all
cases. Successful valve replacement was associated with an increase in
transthoracic echocardiographic valve area from 0.65 +/- 0.14 to 2.2 +/- 0.4 cm2 
and significant improvement in clinical condition. During the course of this
experience, we encountered three (13.6%) cases of vascular complications related 
to transcatheter aortic valve implantation procedures. CONCLUSION: The present
study confirms the excellent hemodynamic performances of the
transcatheter-implanted aortic prosthesis, with both transarterial and
transapical approaches, in inoperable candidates with end-stage aortic stenosis. 
With progressive improvement in patient selection, techniques, equipment, and
operator endovascular skills, vascular complications can decline further.

J Crit Care. 2009 May 7. [Epub ahead of print]

Patterns and prognostic value of troponin, interleukin-6, and leptin after
pediatric open-heart surgery.

Modan-Moses D, Prince A, Kanety H, Pariente C, Dagan O, Roller M, Vishne T,
Efrati O, Paret G.

Pediatric Endocrinology Unit, Chaim Sheba Medical Center, Tel-Hashomer 52621,
Israel; The Sackler school of medicine, Tel-Aviv University, Tel-Aviv 69978,
Israel.

PURPOSE: Leptin and interleukin-6 (IL-6) are inversely correlated and associated 
with decreased survival in critically ill patients. We investigated changes in
leptin, IL-6, and troponin in children undergoing open-heart surgery,
hypothesizing that IL-6 and troponin will increase after cardiopulmonary bypass
(CPB) and will be negatively correlated with leptin. PATIENTS AND METHODS: Serial
blood samples were collected from 21 patients 24 hours before and up to 48 hours 
after surgery. RESULTS: Leptin levels decreased by 50% during CPB (P < .001),
then gradually increased, reaching baseline levels 12 hours after surgery. The
IL-6 levels increased (P < .001) during CPB, peaking 2 hours after surgery and
remaining slightly elevated at 24 hours after surgery (P < .001). Leptin and IL-6
were negatively correlated (R = -0.448, P < .001). Troponin levels increased
during CPB (P < .001). Postoperative leptin and troponin were inversely
correlated (r = -0.535, P < .001). Patients with modest elevations in troponin
levels (<20 mug/L) had a shorter aortic clamp and CPB time (P < .01), lower IL-6 
peak levels (P = .03), and shorter duration of ventilation and inotropic support 
compared with patients with peak troponin levels greater than 20 mug/L.
CONCLUSIONS: Lower leptin and higher IL-6 levels correlated with troponin, a
marker of myocardial injury. Because leptin may have cardioprotective effects,
the postoperative drop in its levels may further contribute to myocardial
dysfunction.

J Thorac Cardiovasc Surg. 2009 May;137(5):1154-62. Epub 2009 Feb 23.

Myocardial membrane injury in pediatric cardiac surgery: An animal model.

Egan JR, Butler TL, Cole AD, Abraham S, Murala JS, Baines D, Street N, Thompson
L, Biecker O, Dittmer J, Cooper S, Au CG, North KN, Winlaw DS.

Kids Heart Research, The Children's Hospital at Westmead, Sydney, Australia.

OBJECTIVE: Reduced myocardial performance invariably follows pediatric cardiac
surgery and is manifested by a low cardiac output state in its severest form. The
role of myocardial membrane proteins in this setting is unknown. Dystrophin and
dysferlin are involved in membrane integrity, whereas aquaporins selectively
transport water. These proteins were examined in a model of pediatric cardiac
surgery, together with a trial of poloxamer 188, which may reduce membrane
injury. METHODS: Eight lambs were randomized to saline with or without poloxamer 
188. Lambs underwent 2 hours of cardiopulmonary bypass and aortic crossclamping. 
After a further 9 hours of monitoring, the hearts were assessed for water
content, capillary leak, and protein expression. RESULTS: Dystrophin expression
was unaffected by ischemia/reperfusion, but dysferlin expression was reduced.
Aquaporin 1 protein increased after ischemia/reperfusion. Poloxamer 188
administration was associated with supranormal levels of dystrophin, preservation
of dysferlin expression, and normalization of aquaporin 1 expression. Poloxamer
188 was associated with less capillary leak, maintained colloid osmotic pressure,
and less hemodilution. Poloxamer 188 was associated with an improved hemodynamic 
profile (higher blood pressure, higher venous saturation, and lower lactate),
although the heart rate tended to be higher. CONCLUSIONS: Changes in protein
expression within the myocardial membrane were found in a clinically relevant
model of pediatric cardiac surgery. Indicators of reduced performance, such as
lower blood pressure and lower oxygen delivery, were lessened in association with
the administration of the membrane protecting poloxamer 188. Poloxamer 188 was
also associated with potentially beneficial changes in membrane protein
expression, reduced capillary leakage, and less hemodilution.

Ann Thorac Surg. 2009 May;87(5):1517-23.

Comment in:
    Ann Thorac Surg. 2009 May;87(5):1523-4.

Pediatric cardioplegia strategy results in enhanced calcium metabolism and lower 
serum troponin T.

O'Brien JD, Howlett SE, Burton HJ, O'Blenes SB, Litz DS, Friesen CL.

Department of Pharmacology, Izaak Walton Killam Health Centre, Dalhousie
University, Halifax, Nova Scotia, Canada.

BACKGROUND: Pediatric myocardium is unique from mature myocardium; thus, the use 
of adult cardioplegia for pediatric cardiac operations may provide suboptimal
myocardial protection. We evaluated our standard adult cardioplegia (AC; modified
Buckberg) and a pediatric cardioplegia (PC) solution (del Nido solution, Baxter) 
in vitro in rat cardiomyocytes and compared short-term outcomes in pediatric
cardiac surgical patients. METHODS: Contractions, intracellular calcium, and
action potentials were recorded from isolated rat cardiomyocytes exposed to PC or
AC, followed by reperfusion. Pediatric patients (n = 118) undergoing cardiac
operations using PC (group PC, n = 59) or AC (group AC, n = 59) were matched 1:1 
for age, diagnosis, and duration of cardiopulmonary bypass. RESULTS: PC-perfused 
rat ventricular cardiomyocytes had lower diastolic calcium during cardioplegia
and early reperfusion than AC-perfused cardiomyocytes. Cardiomyocytes remained
excitable despite introduction of AC but not PC. The mean age in each pediatric
group was 3.7 years (range, 3 days to 17 years; p = 0.95). Median serum troponin 
T levels at intensive care admission were significantly lower in group PC (0.83
+/- 0.25 microg/L) than in group AC (13.8 +/- 12.7 microg/L, p = 0.0001), which
persisted at 24 hours postoperatively. There were no significant differences in
duration of intubation or length of stay in intensive care or the hospital.
CONCLUSIONS: Pediatric cardioplegia is associated with reduced intracellular
diastolic calcium during arrest and reperfusion and more complete arrest during
exposure in rat cardiomyocytes. Pediatric patients receiving pediatric
cardioplegia had reduced troponin T release compared with those receiving adult
cardioplegia.

Crit Care Med. 2009 May;37(5):1685-90.

Comment in:
    Crit Care Med. 2009 May;37(5):1815.

Stress doses of hydrocortisone in high-risk patients undergoing cardiac surgery: 
effects on interleukin-6 to interleukin-10 ratio and early outcome.

Weis F, Beiras-Fernandez A, Schelling G, Briegel J, Lang P, Hauer D, Kreth S,
Kaufmann I, Lamm P, Kilger E.

Department of Anesthesiology, University of Munich, Klinikum Grosshadern, Munich,
Germany. florian.weis@med.uni-muenchen.de

BACKGROUND: Severe systemic inflammation (systemic inflammatory response
syndrome) associated with cardiac surgery often leads to a worse short-term and
long-term outcome. Stress doses of hydrocortisone have been successfully used to 
improve outcome of CS. The interleukin (IL)-6 to IL-10 ratio is associated with
outcome after trauma and major surgery. OBJECTIVE: To evaluate immunologic
effects (especially IL-6 to IL-10 ratio) of stress doses of hydrocortisone in a
high-risk group of patients after cardiac surgery with cardiopulmonary bypass.
DESIGN: Prospective, randomized, double-blinded, placebo-controlled trial.
SETTING: Cardiovascular intensive care unit of a university hospital. PATIENTS:
High-risk patients (n = 36) undergoing CS. INTERVENTION: Stress doses of
hydrocortisone or placebo. MAIN OUTCOME MEASURES: IL-6 to IL-10 ratio and other
markers of systemic inflammation at predefined time points; short-term clinical
outcome. RESULTS: The two study groups did not differ with regard to demographic 
data. The patients from the hydrocortisone group (n = 19) had significantly lower
levels of IL-6 and higher levels of IL-10, resulting in an attenuated change in
IL-6/IL-10 ratio (28.7 [6.4/128.7] vs. 292.8 [6.5/534.6] 4 hours after
cardiopulmonary bypass; p < 0.001). Patients in the hydrocortisone group had a
shorter duration of catecholamine support (1 [1/2] vs. 4 [2/4.5] days; p = 0.02),
a shorter length of stay in the intensive care unit (2 [2/3] vs. 6 [4/8] days; p 
= 0.001), and a lower incidence of postoperative atrial fibrillation (26% vs.
59%; p = 0.04). CONCLUSIONS: Stress doses of hydrocortisone attenuate the
evolution of IL-6/IL-10 ratio in patients with systemic inflammatory response
syndrome after CS, which seems to be associated with an improved outcome. The
immunologic effects of hydrocortisone may thus be both, inhibitory (IL-6) and
permissive (IL-10), regarding the immune response.