Surgical Removal of a Calcified Right Atrial Mass Related to Venous Access Port: A Case Report

INTRODUCTION

Intracardiac masses pose a difficult diagnostic and therapeutic dilemma. Indwelling catheters can lead to thrombus calcification causing untoward sequelae.

CASE PRESENTATION

We report on a patient who presented after computed tomography identified a large calcified right atrial mass. Her history included treatment for rectal cancer and breast cancer, thus we feared the mass could represent metastasis. The intracardiac mass was successfully resected via a right atriotomy. Her postoperative course was uneventful and the histopathology revealed a calcified thrombus.

DISCUSSION

In this report we discuss our findings and pre- and intraoperative considerations, as well as suggestions for management of implantable venous catheters. This is a rare complication of an indwelling catheter.

CONCLUSION

Operative management of intracardiac lesions is the standard of care. When related to implantable catheters, the best patient care would be prevention of such lesions. This would include routine flushing of the indwelling catheters and prompt removal once not in use.

Nicardipine versus Sodium Nitroprusside for Postcardiac Surgery Hypertension: An Evaluation of Effectiveness and Postoperative Costs

Background

Postoperative hypertension after cardiac surgery is associated with substantial morbidity. Both sodium nitroprusside (SNP) and nicardipine (NIC) are effective in its management. Outcomes data for NIC and SNP in persons undergoing cardiac surgery are limited, and there are no data characterizing the influence of drug choice on postoperative costs.

Objective

Our aim was to compare the effectiveness of NIC versus SNP in the management of hypertension after cardiac surgery and evaluate the influence of drug choice on postoperative costs.

Methods

We conducted a retrospective, cohort study using our hospital's financial and electronic medical records. Adults admitted to a cardiothoracic surgical intensive care unit after coronary artery bypass grafting (CABG) and/or valve surgery who developed hypertension requiring ≥30 minutes of NIC or SNP were included. We evaluated drug effectiveness by assessing infusion rate stability, blood pressure and heart rate, and concomitant antihypertensive agent use. Activity-based postoperative costs were compared between study groups.

Results

One hundred twelve subjects were included (NIC = 72, SNP = 40). Hypertension-related demographics were balanced between the groups. NIC was associated with improved infusion rate stability that required fewer dose changes per hour (1.2 ± 1.6) versus SNP (1.7 ± 1.8) ( P = .004). Heart rates and blood pressures did not differ significantly. The number of antihypertensive medications used before and during the NIC or SNP infusions was the same. However, persons who were prescribed SNP required significantly more medications to manage blood pressure after infusions were discontinued ( P = .001). NIC use did not significantly increase postoperative cost. NIC use may be associated with cost increases in isolated CABG but with cost savings in isolated valve or combined CABG/valve surgeries; however, these differences were not statistically significant.

Conclusions

Blood pressure was equally controlled using NIC or SNP. NIC was associated with improved infusion rate stability. Despite a higher acquisition cost, NIC did not significantly influence postoperative costs. Larger, prospective cost-effective analyses in surgical subgroups are needed.

Abstract 288: Secondary Prevention Following Coronary Artery Bypass Surgery: The Need For a Continuum of Care

Purpose: Sustained positive outcomes after coronary artery bypass grafting (CABG) requires risk factor modification and secondary prevention medications. This study assessed the influence of a multidisciplinary educational program on disease understanding, motivation to reduce cardiovascular risk, and secondary prevention medication prescribing following CABG.

Methods: Using a prospective, randomized, controlled design, adults undergoing CABG completed surveys at discharge, 3 months, and 12 months, assessing disease understanding and motivation to reduce cardiovascular risk. Four to six weeks after CABG, intervention subjects completed an educational program involving group discussions and individual counseling with pharmacists, dietitians, and a cardiac rehabilitation nurses. The primary endpoint was a composite score of reduced risk factors, medication use among those eligible, and awareness of prescribed medications. Secondary endpoints evaluated survey scores and medication use rates. Wilcoxon Rank Sum and Chi Square tests compared data between specific time points. Generalized estimating equations and linear contrasts of the parameter estimates compared data at the three time points.

Results: The final analysis included 98 subjects (I=49, C=49). The composite score was not different between groups (I=12.8±4.5 points, C=12.7±4.9 points, p=0.9405). Improvements were noted in understanding and motivation in the entire cohort, but these changes could not be attributed to our intervention. Medication use declined at 3 and 12 months after CABG without significant differences between the groups.

Conclusions: Disease understanding, motivation to reduce risk, and medication use is robust at hospital discharge but declines with time and was not improved by our intervention. These findings are concerning and warrant further study.

Preoperative Statin use is not Associated with a Reduced Risk of Atrial Fibrillation After Cardiac Surgery

Introduction: Postoperative atrial fibrillation (POAF) is prevalent after cardiac surgery and associated with significant morbidity and costs. Statins are commonly used in this population and may be a preventative strategy for PAOF. We wished to examine the effect of preoperative statin use on the risk of POAF after cardiac surgery. Methods: A retrospective, observational study was conducted using data from 489 adult patients who underwent cardiac surgery at a single institution. Univariate analyses and unconditional logistic regression were used to determine the impact of preoperative statin use on the probability of developing POAF, while controlling for the baseline risk of POAF and the use of amiodarone prophylaxis (AMP). A baseline risk index was calculated for each patient using a previously validated model. Patients with chronic atrial fibrillation or missing data were excluded. Results: Mean patient age was 63 (SD=13) years, 73% were male, 68% underwent isolated coronary artery bypass grafting, 16% underwent isolated valve surgery, with 13% underwent combined CABG and valve surgeries, and 3% underwent other forms of cardiac surgery. POAF occurred in 27% of patients receiving statins and 24% of those not receiving statins (p=0.3792). After controlling for baseline risk of POAF and the use of AMP, we found that preoperative statins were not associated with reductions in POAF (OR=1.19, 95%CI=0.782-1.822, p=0.4118). Conclusions: Multiple factors impact the development of POAF after cardiac surgery including patient demographics, comorbidities, surgical type, and concomitant medications. In this study, after adjustment for these factors the preoperative use of statins did not significantly influence the development of POAF.

Risk-Stratified Evaluation of Amiodarone to Prevent Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Amiodarone prophylaxis (AMP) reduces the prevalence of postoperative atrial fibrillation (POAF) after cardiac surgery. We investigated the impact of AMP on the frequency and duration of POAF, the intensive care unit and hospital length of stay, and its cost-effectiveness in a risk-stratified cohort.

METHODS

A retrospective, observational analysis of 509 patients who underwent cardiac surgery in 2003 was performed. Data sources included The Society of Thoracic Surgeons national database; medical and medication administration records; and the activity-based cost data from our institution. Risk stratification for POAF was determined using a validated risk index. Cost-effectiveness was determined from the hospital's perspective.

RESULTS

The mean patient age was 63 years, 27% were female, 80% underwent coronary artery bypass grafting, and 29% underwent valve surgery. When a risk-stratified evaluation was made, 50% of patients were at an elevated risk for having POAF develop. When compared with nonprophylaxed patients, those receiving AMP (59%) experienced less POAF (31% vs 22%; p = 0.027) and shorter durations of POAF (4.7 vs 2.7 days; p = 0.025). In the elevated-risk group, AMP clinically (but not significantly) reduced length of stay in the intensive care unit (101 vs 68 hours; p > 0.05) and post-procedural hospital length of stay (9.7 vs. 7.9 days, p > 0.05). In the elevated-risk group, AMP was robustly cost-effective in reducing POAF.

CONCLUSIONS

Amiodarone prophylaxis reduced the prevalence and duration of POAF. Baseline risk for POAF was a major determinant of the overall cost-effectiveness of AMP. The greatest cost savings with AMP was seen in patients at an elevated risk for POAF. These findings suggest the need for risk stratification when prescribing AMP.

Initial sequencing and analysis of the human genome

The human genome holds an extraordinary trove of information about human development, physiology, medicine and evolution. Here we report the results of an international collaboration to produce and make freely available a draft sequence of the human genome. We also present an initial analysis of the data, describing some of the insights that can be gleaned from the sequence.

Effects of a factor Xa inhibitor, DX-9065a, in a novel rabbit model of venous thrombosis

The objective of this study was to evaluate the effects of DX-9065a, a nonpeptide, direct inhibitor of factor Xa (FXa), in a novel experimental model of venous thrombosis. The experiments were conducted on anesthetized rabbits in which a veno-venous shunt with cotton threads was inserted into the vena cava. DX-9065a was administered intravenously to the rabbits as an initial bolus followed by a maintenance infusion using the following dosing schedules: DX-I: 0.25 mg/kg + 3 micrograms/kg/min.; DX-II: 0.75 mg/kg + 9 micrograms/kg/min.; DX-III: 1.5 mg/kg + 18 micrograms/kg/min.; DX-IV: 3.0 mg/kg + 36 micrograms/kg/min.; DX-V: 6.0 mg/kg + 72 micrograms/kg/min. DX-9065a induced a dose-dependent increase in the time to occlusion and a dose-dependent decrease in thrombus weight. Because of the unique character of the model, we were also able to show a dose-dependent increase in blood flow through the shunt. In addition, there were dose-dependent increases in prothrombin time (PT) and activated coagulation time (ACT) with more variable responses in the activated partial thromboplastin time (APTT). DX-9065a had little effect on thrombin time (TT) or bleeding time at all doses tested. In conclusion, dose-dependent antithrombotic efficacy was documented with DX-9065a in this new model of venous thrombosis. Although the in vivo potency of the compound was not striking, the results support the utility of FXa inhibition in venous thrombosis and demonstrate the utility of this experimental model for evaluating the efficacy of novel anticoagulants.

Structure-activity relationships for 1-phenylbenzimidazoles as selective ATP site inhibitors of the platelet-derived growth factor receptor

1-Phenylbenzimidazoles are shown to be a new class of ATP-site inhibitors of the platelet-derived growth factor receptor (PDGFR). Structure-activity relationships (SARs) are narrow, with closely related heterocycles being inactive. A systematic study of substituted 1-phenylbenzimidazoles showed clear SARs. Substituents at the 4'- and 3'-positions of the phenyl ring are tolerated but do not significantly improve activity, while substituents at the 2'-position abolish it. Substituents in the 2-, 4-, and 7-positions of the benzimidazole ring (with the exception of 4-OH) also abolish activity. Most substituents at the 5- and 6-positions maintain or increase activity, with the 5-OH, 5-OMe, 5-COMe, and 5-CO2Me analogues being >10-fold more potent than the parent 1-phenylbenzimidazole. The 5-OMe analogue was both the most potent inhibitor, and showed the highest selectivity (50-fold) between PDGFR and FGFR isolated enzymes, and also a moderately effective inhibitor (IC50 = 1.9 microM) of PDGF-stimulated PDGFR autophosphorylation in rat aorta smooth muscle cells.

Inhibition of E-selectin-, ICAM-1-, and VCAM-1-mediated cell adhesion by benzo[b]thiophene-, benzofuran-, indole-, and naphthalene-2-carboxamides: identification of PD 144795 as an antiinflammatory agent

It was previously reported that 3-alkoxybenzo[b]thiophene-2-carboxamides exemplified by 1, 5-methoxy-3-(1-methylethoxy)benzo[b]thiophene-2-carboxamide, decreased the adherence of neutrophils to activated endothelial cells by inhibiting the upregulation of the adhesion molecules E-selectin and ICAM-1 on the surface of the endothelium. This finding is extended here to a series of 3-thiobenzo[b]thiophene-2-carboxamides and also heterocyclic analogs of 1, including benzofurans, indoles, and napthalenes. The compounds that inhibited the expression of E-selectin and ICAM-1 had the same effect on the expression of VCAM-1. PD 144795, 5-methoxy-3-(1-methylethoxy)benzo[b]thiophene-2-carboxamide 1-oxide (44), the sulfoxide analog of 1, was orally active in several models of inflammation. The in vitro and in vivo activity of PD 144795 resided predominately in the S-enantiomer.

Hydroxylamine analogs of 2,6-di-t-butylphenols: dual inhibitors of cyclooxygenase and 5-lipoxygenase or selective 5-lipoxygenase inhibitors

The preparation of hydroxylamine analogs of 2,6-di-tert-butylphenols (DTBP) and the inhibition of cyclooxygenase (CO) and 5-lipoxygenase (5-LO) by these compounds is discussed.

A novel prodrug of an impermeant inhibitor of 3-deoxy-D-manno-2-octulosonate cytidylyltransferase has antibacterial activity

Although 8-amino-2,6-anhydro-3,8-dideoxy-D-glycero-D-talo-octonic acid (2) is a potent inhibitor of 3-deoxy-D-manno-octulosonate cytidylyltransferase (CMP-KDO synthetase), it is unable to reach its cytoplasmic target and is therefore inactive as an antibacterial agent. However, esterification of 2 with 8-(hydroxymethyl)-1-naphthyl methyl disulfide (8) generates a prodrug (12), which gains entry into bacterial cells. Intracellular reduction of the disulfide leads to a rapid, intramolecular, displacement of the acid 2, which then inhibits the growth of Gram-negative bacteria by interfering with the biosynthesis of lipopolysaccharide.

Induction of delayed afterdepolarizations and triggered activity in canine Purkinje fibers by lysophosphoglycerides

Lysophosphoglycerides accumulate in ischemic myocardium and induce electrophysiologic alterations in normoxic tissue in vitro closely resembling those seen with ischemia in vivo. Delayed afterdepolarizations and triggered activity may be particularly important in the pathogenesis of arrhythmias in the ischemic heart. The present study was performed to determine whether lysophosphatidylcholine (LPC), at concentrations comparable to those present in ischemic myocardium, can induce delayed afterdepolarizations and/or triggered activity in normoxic canine Purkinje fibers. In the present study, as little as 75 microM LPC was found to induce delayed afterdepolarizations and as little as 100 microM LPC was found to induce delayed afterdepolarizations and triggered activity even at low cycle lengths. The amplitude of the induced delayed afterdepolarizations was enhanced by augmentation of the extracellular concentration of calcium (7 mM) or by exogenous epinephrine (10(-9) to 10(-6) M). The amplitude was decreased by verapamil (1 mg/l) or Mn++ (2.5 mM). Epinephrine at a concentration of 10(-6) M also initiated triggered activity in Purkinje fibers exposed to LPC (75 microM), a response blocked by l-propranolol (2 X 10(-7) M and 10(-6) M) but not by the alpha 1-adrenergic blocking agent BE-2254 (10(-6) M). Delayed afterdepolarizations induced by LPC (75 microM) and epinephrine (10(-6) M) persisted even in the presence of acidosis (pH 6.7) and hyperkalemia ([K+]o = 7 mM). Thus, delayed afterdepolarizations and triggered activity induced by LPC may contribute to the induction and/or maintenance of arrhythmias early after the onset of myocardial ischemia. However, because of the reversal of these effects after superfusion with media devoid of LPC, they may occur with ischemia in vivo but not be seen in tissue isolated from ischemic regions and evaluated in vitro.

Solid-phase purification and analysis of dicarboxylic porphyrins extracted from cultured tumor cells

We describe here a sensitive method for the purification and analysis of porphyrins present in hematoporphyrin derivative. Hematoporphyrin derivative is a solution containing a complex mixture of dicarboxylic porphyrins such as hematoporphyrin IX, monohydroxyethyl monovinyl deuteroporphyrin isomers, and protoporphyrin IX in addition to porphyrin aggregates of variable molecular sizes. This mixture is known for its ability to be selectively retained by tumor cells and for its cytotoxicity in the presence of light. In order to study the mechanisms of hematoporphyrin derivative uptake and its cellular metabolism, extraction methods are required that combine high recoveries with minimum changes of very labile components. Extraction with perchloric acid: methanol mixtures recovered only some 60% of the porphyrins taken up by tumor cells and artifactual fluorescent spots were seen on thin-layer chromatograms. Improved yields were obtained upon extraction with dimethyl sulfoxide or Triton X-100:4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (Hepes) buffer mixture, but the extracts were not suitable for reverse-phase thin-layer chromatography (RTLC). The procedure described here consists of extracting porphyrins from cultured tumor cells with a buffered detergent followed by sequential chromatography on DEAE-cellulose columns and on reverse-phase octadecylsilyl cartridges. Identification of the isolated free dicarboxylic porphyrins is conveniently done by RTLC.

Simultaneous computer mapping to facilitate intraoperative localization of accessory pathways in patients with Wolff-Parkinson-White syndrome

Sixteen patients with the Wolff-Parkinson-White syndrome underwent simultaneous intraoperative computer mapping from multiple sites before surgical division of the accessory pathways. A 16-bipolar electrode band was positioned around the atrioventricular groove. Ventricular epicardial electrograms from single beats were recorded simultaneously during atrial pacing, resulting in maximal preexcitation, and atrial electrograms were recorded during orthodromic supraventricular tachycardia. Four-level transmural plunge needle electrodes were used concomitantly in 3 patients. Electrograms were processed separately using a guarded signal conditioner that isolates, amplifies, filters and analog-to-digitally converts synchronously at 2 kHz with 12-bit accuracy. Digital data were transmitted by fiber optics to a high-density digital recorder and processed with a computer having rapid interactive graphics. Results in the 16 patients revealed 20 distinct Kent bundles. Two patients had only nonsustained supraventricular tachycardia induced intraoperatively and 1 patient manifested intermittent anterograde ventricular preexcitation. Multiple pathways were identified in 4 patients. This simultaneous multiple electrode mapping procedure facilitates intraoperative mapping by requiring only a single beat for analysis of anterograde and retrograde activation times, decreases cardiac manipulation during mapping and obviates the need for cardiopulmonary bypass, and permits analysis of transmural activation patterns. This approach decreases markedly the time required for mapping and permits accurate study of nonsustained arrhythmias as well as rapid identification of multiple accessory pathways.

Intramural reentry as a mechanism of ventricular tachycardia during evolving canine myocardial infarction

We evaluated the contribution of intramural electrical events in initiation and maintenance of ventricular tachycardia in 15 dogs 3-8 days after either permanent (n = 2) or transient (n = 13) coronary artery occlusion. Seven of the dogs (47%) demonstrated eight distinct monomorphic ventricular tachycardia patterns which were mapped by means of a recently designed computerized system capable of simultaneously detecting, storing, and assessing information from 232 individual cardiac sites. Using both epicardial and intramural electrodes, we found definitive evidence for intramural reentry in seven of the eight monomorphic tachycardias analyzed. Furthermore, five of these animals (71%) demonstrated microreentry, in which small epicardial conduction loops exited intermittently into nonrefractory subendocardium to initiate succeeding beats, while, in the remaining two dogs, ventricular tachycardia was due to macroreentry, during which the broad subendocardial wavefronts depolarizing the ventricle constituted the proximal (fast) reentry limbs. Detailed anatomical analysis of the resultant infarcts demonstrated the thin surviving epicardial tissue rim to be the site of conduction delay necessary for reentry, whereas "preferred pathways" of exit into the subendocardial plane occurred at the infarct borders and were of variable configuration. Successful interruption of these rhythms should accompany interference with the process of exit into nonrefractory subendocardial tissue.

In vivo inhibition of thromboxane synthetase in infarcted canine myocardium

The in vivo effectiveness of the thromboxane synthetase inhibitor OKY-1581 was tested in normal and infarcted canine myocardium. A rapid in vitro assay was developed which permits an accurate assessment of the status of the tissue thromboxane synthetase at the time of sacrifice. Reperfused infarcts were created by two hours of coronary artery occlusion followed by release of occlusion and three days of recovery. OKY-1581 was infused at 100 micrograms/kg/min for 15 minutes, a dose previously found to cause an 85% inhibition of canine platelet thromboxane synthetase in vivo. The heart was rapidly excised and transmural tissue plugs of infarcted and normal areas were obtained. These were incubated for 5 minutes with prostaglandin endoperoxide (PGH2) in phosphate buffer. Thromboxane production was inhibited from 16 +/- 1 ng TxB2 per tissue plug to 5 +/- 1 in normal myocardium and from 27 +/- 5 to 6 +/- 1 in infarcted areas of myocardium. Control incubations showed no further inhibition with the in vitro addition of 20 micrograms/ml OKY-1581, confirming the completeness of in vivo inhibition. Thus significant inhibition of thromboxane synthetase by intravenous OKY-1581 occurs even in a reperfused zone of infarction.

Increased alpha-adrenergic receptors in ischemic cat myocardium. A potential mediator of electrophysiological derangements

We have recently demonstrated enhanced alpha-adrenergic responsiveness assessed electrophysiologically in ischemic and reperfused myocardium. This study was performed to determine whether ischemia alters alpha 1-adrenergic receptor number (Bmax) of affinity (KD) based on [3H]prazosin binding. Within 30 min after occlusion, Bmax increased in ischemic regions to 207% of control to 27 +/- 2 fmol/mg protein, with the increase persisting (+ 141% of control) during early reperfusion (2 min), before returning to control base-line values (13 +/- 1.6) after 15 min of reperfusion. KD was not altered at any interval studied. Beta receptor number of ([3H]dihydroalprenolol) and Na+-K+ ATPase activity were comparable in control compared to ischemic myocardium although beta-receptor Bmax and KD in both regions decreased during early reperfusion. Thus, the enhanced alpha-adrenergic responsivity previously recognized with ischemia and reperfusion is correlated with an increase in alpha 1-adrenergic receptors.