Brian J. Potter

Fluids after cardiac surgery: A pilot study of the use of colloids versus crystalloids*

Objectives:To determine whether a starch solution for volume resuscitation in a flow-based protocol improves circulatory status better than a crystalloid solution, as defined by the need for catecholamines in patients the morning after cardiac surgery, and whether this can be performed without increased morbidity. Design:Concealed, randomized, double-blind, controlled trial. Participants:Two hundred sixty-two patients who underwent cardiac surgery at a tertiary care hospital. Interventions:Based on predefined criteria indicating a need for fluids, and a nurse-delivered algorithm that used central venous pressure and cardiac index obtained from a pulmonary artery catheter, patients were allocated to receive 250-mL boluses of 0.9% saline or a 250-molecular weight 10% solution of pentastarch. Results:Two hundred thirty-seven patients received volume boluses: 119 hydroxyethyl starches and 118 saline. Between 8:00 am and 9:00 am the morning after surgery, 13 (10.9%) of hydroxyethyl starch patients and 34 (28.8%) saline patients were using catecholamines (p = .001). Hydroxyethyl starch patients had less pneumonia and mediastinal infections (p = .03) and less cardiac pacing (p = .03). There were two deaths in each group. There was no difference in the daily creatinine, development of RIFLE risk criteria during hospital stay, or new dialysis. The numbers and volumes of packed red blood cells were similar in the two groups, but more hydroxyethyl starch patients received plasma transfusions (p = .05). Conclusions:Use of a colloid solution for volume resuscitation in a nurse-delivered flow-based algorithm, which included a pulmonary artery catheter, significantly improved hemodynamic status, an important factor for readiness for discharge from the intensive care unit.

Effect of Aspirin and warfarin therapy on thromboembolic events in patients with univentricular hearts and Fontan palliation

BACKGROUND Patients with univentricular hearts and Fontan palliation are at risk for thromboembolic complications. While aspirin and warfarin therapies are currently the mainstay of prophylaxis, controversy exists as to the optimal prevention strategy. METHODS A cohort study was conducted on the New England registry of patients born in 1985 or earlier with Fontan surgery at Boston Childrens Hospital, in order to assess and compare the effect of prophylactic aspirin and warfarin on incident thromboembolic events. RESULTS A total of 210 qualifying patients (49% male) underwent Fontan surgery at a median age of 8.5 years: 48.6% had a right atrium to pulmonary artery anastomosis, 11% a right atrium to right ventricle conduit, 38.6% a lateral tunnel, and 1.9% an extracardiac conduit. No thromboembolic prophylaxis was prescribed to 50.0%, whereas 24.3% received aspirin, and 25.7% warfarin. In multivariate analyses, lack of aspirin or warfarin was associated with a significantly higher thromboembolic event rate when compared to therapy with either [hazard ratio 8.5, 95% confidence interval (3.6-19.9), P < 0.001], with no difference between the two treatment strategies (P = 0.768). Twenty-year freedom from thromboemboli was 86% versus 52% in patients with and without thromboprophylaxis, respectively. Other factors independently associated with thromboemboli were a low post-operative cardiac index [hazard ratio 2.6, 95% confidence interval (1.2, 5.9)] and atrial fibrillation or flutter [hazard ratio 3.1, 95% confidence interval (1.2, 8.0)]. CONCLUSIONS Prophylaxis with either aspirin or warfarin was associated with a significantly lower rate of incident thromboembolic events following Fontan palliation, with no difference between the two therapies.

Calcineurin inhibitor substitution with sirolimus vs. reduced‐dose calcineurin inhibitor plus sirolimus is associated with improved renal dysfunction in heart transplant patients

Abstract:  Heart transplant (HTx) patients are at risk of developing renal dysfunction. Sirolimus has been used as an alternative for calcineurin inhibitors (CNI) in transplant patients with renal dysfunction. Recent data suggest that the combination of sirolimus with a CNI is associated with a deterioration of renal function in renal transplant patients. The purpose of the present study was to compare the effect on the creatinine clearance (CrCl) of heart transplant (HTx) patients with renal dysfunction (RD) on CNI‐based sirolimus‐free regimens of conversion to either reduced‐dose CNI plus sirolimus or outright substitution of CNI with sirolimus. We retrospectively identified 29 treatment switches for 26 patients with RD defined as a decline in the CrCl > 25% post‐HTx. Treatment switches were divided into two groups. Group 1 included 13 switches in 13 patients (four women, nine men, age 62 ± 10 yr) in whom sirolimus replaced CNI. Group 2 included 16 switches in 15 patients [two women, 13 men (one man underwent two such switches), age 61 ± 9 yr] in whom CNI dose was reduced and sirolimus was added. Two men appear in both groups. Average follow‐up was 10.4 ± 3.2 months. Overall mortality, rejection, and side‐effects rates were comparable between groups. At 12‐months post‐switch, the mean CrCl had increased from 48 ± 15 at time of treatment switch to 56 ± 22 mL/min in group 1 and decreased from 53 ± 19 to 47 ± 17 mL/min in group 2 (p = 0.02). In conclusion, substitution of CNI with sirolimus provided improved renal recovery compared with lower‐dose CNI plus sirolimus in HTx patients with renal dysfunction.

Hemodynamic and Clinical Benefits Associated With Chronic Sildenafil Therapy in Advanced Heart Failure: Experience of the Montréal Heart Institute

BACKGROUND Pulmonary hypertension is highly prevalent in advanced heart failure (HF) despite optimal medical and device therapies. The objective of this investigation was to report on a single centres experience of open-label chronic sildenafil therapy in patients with advanced HF. METHODS We conducted a retrospective systematic medical record review of all patients evaluated at our institution for heart transplantation who had also been treated with chronic sildenafil therapy. Baseline demographics, comorbidities, and concomitant medications, as well as the results of laboratory investigations and physiological testing, were abstracted from patient medical records. Change in systolic and mean pulmonary artery pressure (PAP), transpulmonary gradient, cardiac output and cardiac index, and selected laboratory parameters was analyzed by means of the Wilcoxon rank sum test. Outcomes of interest included New York Heart Association (NYHA) functional class after 6 months of therapy and adverse effects attributable to sildenafil. RESULTS The 16 patients undergoing evaluation for cardiac transplantation combined for 4166 patient-days on sildenafil, with a mean dose of 102.5 ± 54.0 mg/d. None discontinued because of side effects. At 6 months, there was an improvement in the cardiac index (P = 0.014) and systolic PAP (P = 0.049) without any significant change in other hemodynamic parameters. Ten patients (62.5%) experienced an improvement in their NYHA functional class, 8 (50%) received a heart transplantation, and 2 (12.5%) improved sufficiently to be removed from the transplant list. CONCLUSION Chronic sildenafil therapy was well tolerated and associated with improved functional capacity and decreased systolic PAP. Properly controlled randomized studies of the long-term usefulness of sildenafil therapy in advanced HF populations are warranted.

Cardiac output responses in a flow-driven protocol of resuscitation following cardiac surgery ☆,☆☆

OBJECTIVE Determine the role of cardiac output and central venous pressure (CVP) measurements in the clinical decisions that were based on the algorithm used in a randomized trial that compared a colloid to a crystalloid solution in the management of patients early after cardiac surgery (FACS trial, NCT00337805, Crit Care Med 2010; 38:2117). METHODS We analyzed the changes in CVP and cardiac index (CI) in 729 fluid challenges from the FACS trial in which 119 patients were randomized to colloid and 118 to crystalloid boluses in a flow-based protocol. A fluid challenge was defined as being positive if CI increased by ≥ 0.3 L/min(-1)m(-2) and negative if CI increased by <0.3 L/min(-1)m(-2) but CVP increased by ≥ 2 mmHg. RESULTS As defined in the protocol, 26% of boluses were given for a low CI (<2.2 L/min(-1)m(-2)). CI did not increase in 20% of boluses despite an adequate increase in CVP; in the protocol this meant that further volume boluses were not given. In another 34% of boluses in which CI did not increase, CVP increased by < 2 mmHg, which meant that volume responsiveness could not be ruled out and another bolus was indicated. 43% of the boluses were given for hypotension, but surprisingly in 90% of these instances, CI was in the acceptable range indicating that the low arterial pressure was due to decreased systemic vascular resistance. CONCLUSION Measurement of cardiac output and CVP significantly influenced clinical decisions in the FACS algorithm.

Association between quantity and duration of snowfall and risk of myocardial infarction

BACKGROUND: Although aggregate data suggest a link between snowfall and myocardial infarction (MI), individual risk has yet to be assessed. We evaluated the association between quantity and duration of snowfall and the risk of MI using nonaggregated administrative health data. METHODS: We used a case–crossover study design to investigate the association between snowfall and hospital admission or death due to MI in the province of Quebec, Canada, between November and April during 1981–2014. The main exposure measures were quantity (in centimetres) and duration (in hours) of snowfall by calendar day. We computed odds ratios (ORs) and 95% confidence intervals (CIs) for the association between daily snowfall and MI, adjusted for minimum daily temperatures. RESULTS: In all, 128 073 individual hospital admissions and 68 155 deaths due to MI were included in the analyses. The likelihood of MI was increased the day after a snowfall among men but not among women. Compared with 0 cm, 20 cm of snowfall was associated with an OR of 1.16 for hospital admission (95% CI 1.11–1.21) and 1.34 for death (95% CI 1.26–1.42) due to MI the following day among men. Corresponding ORs among women were 1.01 (95% CI 0.95–1.07) and 1.04 (95% CI 0.96–1.13). Similar but smaller associations were observed for snowfall duration (0 h v. 24 h) and MI. INTERPRETATION: Both the quantity and duration of snowfall were associated with subsequent risk of hospital admission or death due to MI, driven primarily by an effect in men. These data have implications for public health initiatives in regions with snowstorms.

The first case of takotsubo cardiomyopathy associated with sodium tetradecyl sulphate sclerotherapy

The present article describes the case of a 70-year-old woman who developed a classic type takotsubo cardiomyopathy after receiving cosmetic sclerotherapy for varicose veins of the legs with sodium tetradecyl sulphate (STS) injections. The patient was in her usual state of health before the injections, and described no apprehension leading up to the procedure and no pain during the procedure. However, a few minutes after the completion of the procedure, the patient had severe chest pain of sudden onset and an electrocardiogram highly suggestive of ST elevation myocardial infarction. The patient was referred for emergent coronary angiography, which was normal. Subsequent ventriculography confirmed the suspected apical ballooning typical of takotsubo cardiomyopathy. Ventricular function returned to near-normal within three days of presentation. The present article describes what is believed to be the first case of takotsubo cardiomyopathy associated with the use of STS. A review of adverse events ascribed to STS revealed visual disturbances and transient ischemic attacks, suggesting the possibility of a common underlying vasospastic pathophysiology and an under- recognized vasoactive potential of STS that merits further investigation. In the interim, the present case advocates for the recommendation of universal pretreatment test dosing.

Impact of the direct transfer to percutaneous coronary intervention-capable hospitals on survival to hospital discharge for patients with out-of-hospital cardiac arrest

AIMS Patients suffering from out-of-hospital cardiac arrest (OHCA) are frequently transported to the closest hospital. Percutaneous coronary intervention (PCI) is often indicated following OHCA. This studys primary objective was to determine the association between being transported to a PCI-capable hospital and survival to discharge for patients with OHCA. The additional delay to hospital arrival which could offset a potential increase in survival associated with being transported to a PCI-capable center was also evaluated. METHODS This study used a registry of OHCA in Montreal, Canada. Adult patients transported to a hospital following a non-traumatic OHCA were included. Hospitals were dichotomized based on whether PCI was available on-site or not. The effect of hospital type on survival to discharge was assessed using a multivariable logistic regression. The added prehospital delay which could offset the increase in survival associated with being transported to a PCI-capable center was calculated using that regression. RESULTS A total of 4922 patients were included, of whom 2389 (48%) were transported to a PCI-capable hospital and 2533 (52%) to a non-PCI-capable hospital. There was an association between being transported to a PCI-capable center and survival to discharge (adjusted odds ratio = 1.60 [95% confidence interval 1.25-2.05], p < .001). Increasing the delay from call to hospital arrival by 14.0 min would offset the potential benefit of being transported to a PCI-capable center. CONCLUSIONS It could be advantageous to redirect patients suffering from OHCA patients to PCI-capable centers if the resulting expected delay is of less than 14 min.

Time trends in antithrombotic management of patients with atrial fibrillation treated with coronary stents: Results from TALENT-AF (The internAtionaL stENT - Atrial Fibrillation study) multicenter registry

Antithrombotic management of patients with atrial fibrillation (AF) requiring percutaneous coronary intervention (PCI) is highly variable; limited evidence‐based guidelines exist to influence practice.

Long-Term Risk of Cardiovascular Disease in Women Who Have Had Infants With Heart Defects

Background: The possibility that congenital heart defects signal a familial predisposition to cardiovascular disease has not been investigated. We aimed to determine whether the risk of cardiovascular disorders later in life was higher for women who have had newborns with congenital heart defects. Methods: We studied a cohort of 1 084 251 women who had delivered infants between 1989 and 2013 in Quebec, Canada. We identified women whose infants had critical, noncritical, or no heart defects, and tracked the women over time for future hospitalizations for cardiovascular disease, with follow-up extending up to 25 years past pregnancy. We calculated the incidence of cardiovascular hospitalization per 1000 person-years, and used Cox proportional hazards regression to estimate hazard ratios and 95% confidence intervals (CIs) for the association between infant heart defects and risk of maternal cardiovascular hospitalization. Models were adjusted for age, parity, preeclampsia, comorbidity, material deprivation, and time period. Results: Women whose infants had heart defects had a higher overall incidence of cardiovascular hospitalization. There were 3.38 cardiovascular hospitalizations per 1000 person-years for those with critical defects (95% CI, 2.67–4.27), 3.19 for noncritical defects (95% CI, 2.96–3.45), and 2.42 for no heart defects (95% CI, 2.39–2.44). In comparison with no heart defects, women whose infants had critical defects had a hazard ratio of 1.43 (95% CI, 1.13–1.82) for any cardiovascular hospitalization, and women whose infants had noncritical defects had a hazard ratio of 1.24 (95% CI, 1.15–1.34), in adjusted models. Risks of specific causes of cardiovascular hospitalization, including myocardial infarction, heart failure, and other atherosclerotic disorders, were also greater for mothers of infants with congenital heart defects than with no defects. Conclusions: Women whose infants have congenital heart defects have a greater risk of cardiovascular hospitalization later in life. Congenital heart defects in offspring may be an early marker of predisposition to cardiovascular disease.