TOP TEN SELECTED PAPERS - October 2009

1

J Coll Physicians Surg Pak. 2009 Nov;19(11):682-5.

Bidirectional Glenn Shunt without Cardiopulmonary Bypass.

Hussain A, Saleem K, Inam-Ullah, Ahmed I, Younus U, Rashid A.

Department of Cardiac Surgery, Armed Forces Institute of Cardiology/National
Institute of Heart Diseases, Rawalpindi.

Objective: To determine the efficacy of bidirectional Glenn shunt (BDG) without
cardiopulmonary bypass (CPB). Study Design: Quasi experimental study. Place and
Duration of Study: The Armed Forces Institute of Cardiology and National
Institute of Heart Diseases (AFICNIHD), Rawalpindi. Methodology: Thirty one
patients underwent BDG without CPB between January 2006 to December 2007.
Subjects for off pump BDG were those who did not require any intracardiac repair,
had good sized branch pulmonary arteries, had acceptable PA pressures (< 16 mm
Hg), and did not have any significant atrio-ventricular (AV) valve regurgitation.
The off pump BDG was performed using veno-venous shunt between the superior vena 
cava (SVC) and right atrium (RA) following heparinization. All patients underwent
discharge echocardiography to assess BDG patency. Statistical significance was
determined using t-test with statistical significance at p < 0.05. Results: There
were 18 males and 13 females. All patients survived. Twenty seven (87.09%)
patients received BDG and 04 patients (12.90%) received bilateral BDG. Atrial
septectomy with inflow occlusion was performed in 5 patients. Antegrade pulmonary
blood flow was left in 24 (77.41%) of 31 patients. There was significant
improvement in postoperative SpO2 (p = 0.000) in all the cases. There were no
postoperative neurologic complications. Sepsis occurred in 2 patients who
ultimately recovered. One patient had chylothorax which stopped after three (03) 
days in ICU. No SVC/PA distortions were noted by discharge echocardiography.
Eliminating CPB reduced the cost of the procedure substantially and saved the
patients from its inherent complications. Conclusion: BDG without CPB is a safe
procedure in selected patients. It avoids CPB related problems and is cost
effective, with excellent results.

Acta Anaesthesiol Scand. 2009 Oct 29. [Epub ahead of print]

Infusion of hypertonic saline/starch during cardiopulmonary bypass reduces fluid 
overload and may impact cardiac function.

Kvalheim VL, Farstad M, Steien E, Mongstad A, Borge BA, Kvitting PM, Husby P.

Section for Cardiothoracic Surgery, Department of Heart Disease, University of
Bergen, Haukeland University Hospital, Bergen, Norway.

Objective: Peri-operative fluid accumulation resulting in myocardial and
pulmonary tissue edema is one possible mechanism behind post-operative
cardiopulmonary dysfunction. This study aimed to confirm an improvement of
cardiopulmonary function by reducing fluid loading during an open-heart surgery. 
Materials and methods: Forty-nine elective CABG patients were randomized to an
intraoperative infusion of hypertonic saline/hydroxyethyl starch (HSH group) or
Ringer's solution (CT group). Both groups received 1 ml/kg/h of the study
solution for 4 h after baseline values were obtained (PICCO((R)) transpulmonary
thermodilution technique). Net fluid balance (NFB), hemodynamic and laboratory
parameters were measured. Results: NFB was four times higher in the CT group
compared with the HSH group during the first 6 h post-operatively. The total
fluid gain until the next morning was lower in the HSH group, 2993.9 (938.6) ml, 
compared with the CT group, 4298.7 (1059.3) ml (P<0.001). Normalized values
(i.e., %-changes from the baseline) of the cardiac index and the global end
diastolic volume index increased post-operatively in both groups. Both parameters
were significantly higher at 6 h in the HSH group compared with CT group (P=0.002
and 0.005, respectively). Normalized values of the intrathoracic blood volume
index were lower in the HSH group at 6 h post-operatively when compared with the 
CT group. The PaO(2)/FiO(2) ratio decreased similarly in both groups early
post-operatively, but recovery tended to be more rapid in the HSH group. Although
serum-sodium and serum-chloride levels were significantly higher in the HSH
group, the acid-base parameters remained similar and within the normal range.
Conclusions: An intraoperative infusion of HSH during cardiac surgery contributes
to reduced fluid loading and an improvement in the post-operative cardiac
performance. No adverse effects of the HSH infusion were observed.

J Cardiothorac Vasc Anesth. 2009 Oct 27. [Epub ahead of print]

Prophylactic Vasopressin in Patients Receiving the Angiotensin-Converting Enzyme 
Inhibitor Ramipril Undergoing Coronary Artery Bypass Graft Surgery.

Hasija S, Makhija N, Chowdhury M, Hote M, Chauhan S, Kiran U.

Department of Cardiac Anaesthesia, Cardiothoracic Centre, All India Institute of 
Medical Sciences, Ansari Nagar, New Delhi, India.

OBJECTIVE: The purpose of this study was to compare the effects of continuation
versus discontinuation of the angiotensin-converting enzyme (ACE) inhibitor
ramipril and assess the efficacy of prophylactic vasopressin infusion on
hemodynamic stability and vasoactive drug requirements in patients undergoing
coronary artery bypass graft (CABG) surgery. DESIGN: A prospective, randomized,
double-blinded, single-center clinical study. SETTING: Tertiary care hospital.
PARTICIPANTS: Forty-seven patients on the ACE inhibitor ramipril for 6 weeks
before undergoing elective primary CABG surgery on cardiopulmonary bypass (CPB). 
INTERVENTIONS: Patients were randomly divided into 3 groups: group A (n = 16),
patients discontinued ramipril 24 hours before surgery; group B (n = 16),
patients continued ramipril until the morning of surgery; and group C (n = 15),
patients continued ramipril until the morning of surgery and received vasopressin
infusion (0.03 U/min) from the onset of rewarming until the hemodynamics were
stable without vasopressor agents. The anesthetic technique and conduct of CPB
were standardized for all the groups. Hemodynamic parameters and vasoactive drug 
requirements were recorded for 3 days postoperatively. MEASUREMENTS AND MAIN
RESULTS: Patients in group A maintained stable mean arterial pressure (MAP) and
systemic vascular resistance (SVR). In group B, MAP and SVR decreased after the
induction of anesthesia and remained so throughout surgery (p < 0.05). In group
C, MAP and SVR decreased upon the induction of anesthesia (p < 0.05) but
normalized after CPB. CONCLUSIONS: Preoperative ACE inhibitor continuation
predisposed to hypotension upon the induction of anesthesia and in the post-CPB
period. Prophylactic low-dose vasopressin infusion prevented post-CPB
hypotension. Low-dose vasopressin can be considered as potential therapy in these
patients.

Anesth Analg. 2009 Oct 27. [Epub ahead of print]

Heparin Concentration-Based Anticoagulation for Cardiac Surgery Fails to Reliably
Predict Heparin Bolus Dose Requirements.

Garvin S, Fitzgerald DC, Despotis G, Shekar P, Body SC.

From the *Department of Anesthesiology, Perioperative and Pain Medicine, and.

Background: Hemostasis management has evolved to include sophisticated
point-of-care systems that provide individualized dosing through heparin
concentration-based anticoagulation. The Hepcon HMS Plus system (Medtronic,
Minneapolis, MN) estimates heparin dose, activated clotting time (ACT), and
heparin dose response (HDR). However, the accuracy of this test has not been
systematically evaluated in large cohorts. Methods: We examined institutional
databases for all patients who underwent cardiac surgery with cardiopulmonary
bypass (CPB) at our institution from February 2005 to July 2008. During this
period, the Hepcon HMS Plus was used exclusively for assessment of heparin dosing
and coagulation monitoring. Detailed demographic, surgical, laboratory, and
heparin dosing data were recorded. ACT, calculated and measured HDR, and heparin 
concentrations were recorded. Performance of the Hepcon HMS Plus was assessed by 
comparison of actual and target ACT values and calculated and measured HDR.
Results: In 3880 patients undergoing cardiac surgery, heparin bolus dosing to a
target ACT resulted in wide variation in the postheparin ACT (r(2) = 0.03). The
postheparin ACT did not reach the target ACT threshold in 7.4% (i.e., when target
ACT was 300 s) and 16.9% (i.e., when target ACT was 350 s) of patients.
Similarly, the target heparin level calculated from the HDR did not correlate
with the postbolus heparin level, with 18.5% of samples differing by more than 2 
levels of the assay. Calculated and measured HDR were not linearly related at any
heparin level. Conclusions: The Hepcon HMS Plus system poorly estimates heparin
bolus requirements in the pre-CPB period. Further prospective studies are needed 
to elucidate what constitutes adequate anticoagulation for CPB and how clinicians
can reliably and practically assess anticoagulation in the operating room.

Crit Care. 2009 Oct 19;13(5):R165. [Epub ahead of print]

Statin prophylaxis and inflammatory mediators following cardiopulmonary bypass: a
systematic review.

Morgan C, Zappitelli M, Gill P.

ABSTRACT: INTRODUCTION: Induction of an inflammatory response is thought to have 
a significant role in the complications that follow cardiopulmonary bypass (CPB).
The statin drugs are increasingly being recognized as having potent
anti-inflammatory effects and hence have potential to influence an important
mechanism of injury in CPB, although there is no current confirmation that this
is indeed the case. Our objective was to systematically review if pre-operative
prophylactic statin therapy, compared with placebo or standard of care, can
decrease the inflammatory response in people undergoing heart surgery with CPB.
METHODS: We performed a systematic and comprehensive literature search for all
randomized controlled trials (RCTs) of open heart surgery with CPB in adults or
children who received prophylactic statin treatment prior to CPB, with reported
outcomes which included markers of inflammation. Two authors independently
identified eligible studies, extracted data, and assessed study quality using
standardized instruments. Weighted mean difference (WMD) was the primary summary 
statistic with data pooled using a random effects model. Descriptive analysis was
used when data could not be pooled. RESULTS: Eight RCTs were included in the
review, with the number of trials for each inflammatory outcome being even more
limited. Pooled data demonstrated benefit with the use of statin to attenuate the
post-CPB increase in interleukins 6 and 8 (IL-6, IL-8), peak high sensitivity
C-reactive protein (hsCRP), and tumor necrosis factor-alpha (TNF- alpha) post-CPB
(WMD [95% confidence interval (CI)] -23.5 pg/ml [-36.6 to -10.5]; -23.4 pg/ml
[-35.8 to -11.0]; -15.3 mg/L [CI -26.9 to -3.7]; -2.10 pg/ml [-3.83 to -0.37]
respectively). Very limited RCT evidence suggests that prophylactic statin
therapy may also decrease adhesion molecules following CPB including neutrophil
CD11b and soluble P (sP)-selectin. CONCLUSIONS: Although the RCT evidence may
suggest a reduction in post-CPB inflammation by statin therapy, the evidence is
not definitive due to significant limitations. Several of the trials were not
methodologically rigorous and statin intervention was highly variable in this
small number of studies. This systematic review demonstrates that there is a
significant gap that exists in the current literature in regards to the potential
anti-inflammatory effect of statin therapy prior to CPB.

World J Surg. 2009 Oct 17. [Epub ahead of print]

Eight-Year Experience with Minimally Invasive Cardiothoracic Surgery.

Iribarne A, Karpenko A, Russo MJ, Cheema F, Umann T, Oz MC, Smith CR, Argenziano 
M.

Division of Cardiothoracic Surgery, Department of Surgery, College of Physicians 
and Surgeons, Columbia University Medical Center, 77 Fort Washington Avenue,
Milstein Hospital, Suite 7-435, New York, NY, 10032, USA, ai2141@columbia.edu.

BACKGROUND: Over the past decade, minimally invasive cardiac surgery (MICS) has
emerged as an accepted approach for the management of cardiac disease that
requires a surgical solution. We report the results of an 8-year,
single-institution experience with MICS. METHODS: Between January 1, 2000 and
December 31, 2007, a total of 910 patients underwent MICS. Major cases included
aortic valve procedures (71, 7.8%), coronary artery bypass grafting (96, 10.5%), 
atrioseptal defect repair (103, 11.3%), and mitral valve procedures (507, 55.7%).
Major outcomes of interest included the complication and mortality rates.
RESULTS: The mean age of the patients was 57 +/- 15 years; the mean ejection
fraction was 55% +/- 11%; and the mean body mass index was 26.1 +/- 4.9. Overall,
782 cases (85.9%) were performed through a mini-thoracotomy. Most of the cases
were accomplished through central cannulation (765, 84.0%), and venous drainage
was most commonly performed in a bicaval fashion (percutaneous superior vena cava
and percutaneous inferior vena cava). The mean aortic cross-clamp and
cardiopulmonary bypass (CPB) times were 58.1 +/- 44.9 and 101.9 +/- 66.8 min,
respectively. Conversion to full sternotomy occurred in 10 patients, and the
median length of stay in hospital was 6 days. The overall complication rate was
8.8%, and the 30-day mortality rate was 2.9%. In the multivariate logistic
regression analysis, risk factors associated with in-hospital complications
included age, CPB time, arterial cannulation location, conversion from off-CPB to
on-CPB, hepatic insufficiency, and diabetes. In the multivariate hazards
regression analysis, risk factors associated with mortality included
postoperative stroke, renal failure, and sternal wound infection; CPB time; and
previous surgery. CONCLUSIONS: In our experience, minimally invasive approaches
are effective and reproducible for a variety of cardiac operations, with
acceptable operating time durations, morbidity, and mortality.

Eur J Cardiothorac Surg. 2009 Oct 13. [Epub ahead of print]

Incidence and prediction of permanent neurological deficits after cardiac surgery
- are the existing models of prediction truly global?

Knapik P, Ciesla D, Wawrzynczyk M, Knapik M, Borkowski J, Zembala M.

Department of Cardiac Anaesthesia and Intensive Therapy, Silesian Centre for
Heart Diseases, Poland.

Objective: Permanent neurological deficit (PND) is a relatively rare but serious 
complication of cardiac surgery, associated with a high mortality and a poor
prognosis for an acceptable quality of life. A few predictive models of PND have 
been developed; however, it is not certain whether they may be extrapolated to
any cardiac surgical population. We aimed to assess the epidemiology and identify
predictors of PND on the basis of a single, prospective hospital database from
Eastern Europe. Methods: We performed a retrospective review of 6016 consecutive 
adult patients (coronary revascularisation with or without cardiopulmonary bypass
- 3613 patients; isolated single-, double- or triple-valve repair or replacement 
- 1221 patients; CABG+valve repair or replacement - 563 patients; aortic aneurysm
surgery - 228 patients; and other procedures - 391 patients). PND was defined as 
a new focal or global disorder of cerebral function lasting longer than 24h and
still present at the time of hospital discharge or the patient's death. Thirty
independent preoperative, intra-operative and postoperative variables that might 
influence PND were selected and analysed. Results: In total, PND was identified
in 2.5% of patients (coronary surgery - 1.7%, isolated valve surgery - 2.9%,
combined procedures - 5.3%, aortic aneurysm surgery - 7.5% and others - 2.2%).
The overall mortality among patients with PND was very high in comparison to the 
remaining patients (40.4% vs 2.2%, p<0.001). In a multivariate analysis, PND was 
associated with five variables: cardiopulmonary bypass time >2h (odds ratio (OR) 
3.35), emergency surgery (OR 3.34), early rethoracotomy (OR 3.17), age >65 years 
(OR 1.70) and unstable course of cardiac disease (OR 1.60). Conclusion: PND after
cardiac operation is associated with a high mortality and poor prognosis. The
incidence of PND varies depending on the procedure. Predictive models of
neurological injury post-cardiac surgery should be more centre-specific.

Circulation. 2009 Oct 27;120(17):1664-71. Epub 2009 Oct 12.

Early on-cardiopulmonary bypass hypotension and other factors associated with
vasoplegic syndrome.

Levin MA, Lin HM, Castillo JG, Adams DH, Reich DL, Fischer GW.

Departments of Anesthesiology, Mount Sinai Medical Center, New York, NY 10029,
USA.

BACKGROUND: Vasoplegic syndrome is a form of vasodilatory shock that can occur
after cardiopulmonary bypass (CPB). We hypothesized that the severity and
duration of the decline in mean arterial pressure immediately after CPB is begun 
can be used as a predictor of patients will develop vasoplegia in the immediate
post-CPB period and of poor clinical outcome. We quantified the decline in mean
arterial pressure by calculating an area above the mean arterial blood pressure
curve. METHODS AND RESULTS: We retrospectively analyzed 2823 adult cardiac
surgery cases performed between July 2002 and December 2006. Of these 2823, 577
(20.4%) were vasoplegic after separation from CPB. We found that 1645 patients
(58.3%) had a clinically significant decline in mean arterial pressure after
starting CPB (area above the mean arterial blood pressure curve >0) and were
significantly more likely to become vasoplegic (23.0% versus 16.9%; odds ratio,
1.26; 95% confidence interval, 1.12 to 1.43; P<0.001). These patients were also
far more likely either to die in hospital or to have a length of stay >10 days
(odds ratio, 3.30; 95% confidence interval, 1.44 to 7.57; P=0.005). Additional
risk factors for developing vasoplegia that were identified included the additive
euroSCORE, procedure type, prebypass mean arterial pressure, length of bypass,
administration of pre-CPB vasopressors, core temperature on CPB, pre- and
post-CPB hematocrit, the preoperative use of beta-blockers or
angiotensin-converting enzyme inhibitors, and the intraoperative use of
aprotinin. CONCLUSIONS: The results of this investigation suggest that it is
possible to predict vasoplegia intraoperatively before separation from CPB and
that the presence of a clinically significant area above the mean arterial blood 
pressure curve serves as a predictor of poor clinical outcome.

Anesth Analg. 2009 Oct 9. [Epub ahead of print]

Postoperative Activity, but Not Preoperative Activity, of Antithrombin Is
Associated with Major Adverse Cardiac Events After Coronary Artery Bypass Graft
Surgery.

Garvin S, Muehlschlegel JD, Perry TE, Chen J, Liu KY, Fox AA, Collard CD, Aranki 
SF, Shernan SK, Body SC.

From the *Department of Anesthesiology, Perioperative and Pain Medicine, Brigham 
and Women's Hospital, Harvard Medical School, Boston, Massachusetts;

Background: Low levels of antithrombin (AT) have been independently associated
with prolonged intensive care unit stay and an increased incidence of neurologic 
and thromboembolic events after cardiac surgery. We hypothesized that
perioperative AT activity is independently associated with postoperative major
adverse cardiac events (MACEs) in patients undergoing coronary artery bypass
graft (CABG) surgery. Methods: We prospectively studied 1403 patients undergoing 
primary CABG surgery with cardiopulmonary bypass (CPB)
(http://clinicaltrials.gov/show/NCT00281164). The primary clinical end point was 
occurrence of MACE, defined as a composite outcome of any one or more of the
following: postoperative death, reoperation for coronary graft occlusion,
myocardial infarction, stroke, pulmonary embolism, or cardiac arrest until first 
hospital discharge. Plasma AT activity was measured before surgery, after
post-CPB protamine, and on postoperative days (PODs) 1-5. Multivariate logistic
regression modeling was performed to estimate the independent effect of
perioperative AT activity upon MACE. Results: MACE occurred in 146 patients
(10.4%), consisting of postoperative mortality (n = 12), myocardial infarction (n
= 108), stroke (n = 17), pulmonary embolism (n = 8), cardiac arrest (n = 16), or 
a subsequent postoperative or catheter-based treatment for graft occlusion (n =
6). AT activity at baseline did not differ between patients with (0.91 +/- 0.13
IU/mL; n = 146) and without (0.92 +/- 0.13 IU/mL; n = 1257) (P = 0.18) MACE. AT
activity in both groups was markedly reduced immediately after CPB and recovered 
to baseline values over the ensuing 5 PODs. Postoperative AT activity was
significantly lower in patients with MACE than those without MACE. After
adjustment for clinical predictors of MACE, AT activity on PODs 2 and 3 was
associated with MACE. Conclusions: Preoperative AT activity is not associated
with MACE after CABG surgery. MACE is independently associated with postoperative
AT activity but only at time points occurring predominantly after the MACE.

J Thorac Cardiovasc Surg. 2009 Oct 9. [Epub ahead of print]

Magnesium supplementation during cardiopulmonary bypass to prevent junctional
ectopic tachycardia after pediatric cardiac surgery: A randomized controlled
study.

Manrique AM, Arroyo M, Lin Y, El Khoudary SR, Colvin E, Lichtenstein S,
Chrysostomou C, Orr R, Jooste E, Davis P, Wearden P, Morell V, Munoz R.

The Department of Pediatrics, Heart Center, Children's Hospital of Pittsburgh,
University of Pittsburgh, Pittsburgh, PA.

OBJECTIVES: We analyzed the role of magnesium sulfate (MgSO(4)) supplementation
during cardiopulmonary bypass in pediatric patients undergoing cardiac surgery,
assessing the incidence of hypomagnesemia and the incidence of junctional ectopic
tachycardia. METHODS: We performed a randomized, double-blind, controlled trial
in 99 children. MgSO(4) or placebo was administered during the rewarming phase of
cardiopulmonary bypass: group 1, placebo group (29 patients); group 2, 25 mg/kg
of MgSO(4) (30 patients); and group 3, 50 mg/kg of MgSO(4) (40 patients).
RESULTS: At the time of admission to the cardiac intensive care unit, groups
receiving MgSO(4) had significantly greater levels of ionized magnesium (group 1,
0.51 +/- 0.07; group 2, 0.57 +/- 0.09; group 3, 0.59 +/- 0.09). Hypomagnesemia
before bypass was common (75%-86.2%) and not significantly different among the
groups. The proportion of hypomagnesemia decreased significantly at admission to 
the cardiac intensive care unit in groups receiving MgSO(4) (group 1, 77.8%;
group 2, 63%; group 3, 47.4%). Patients receiving placebo (group 1) had a
significantly greater occurrence of junctional ectopic tachycardia than groups
receiving MgSO(4) (group 1, n = 5 [17.9%]; group 2, n = 2 [6.7%]; group 3, n = 0 
[0%]). Age (<1 month), Aristotle score (>4), and history of cardiac failure were 
associated with junctional ectopic tachycardia. None of the patients with those
characteristics in group 3 had junctional ectopic tachycardia. No association was
found between study groups and the Pediatric Risk of Mortality score or length of
stay in the cardiac intensive care unit. CONCLUSIONS: Supplementation with
MgSO(4) during cardiopulmonary bypass seems to reduce the incidence of
hypomagnesemia and junctional ectopic tachycardia at admission to the cardiac
intensive care unit. This effect seems to be dose related.