Issues influencing development of the Canadian Cardiovascular Information Network

The 1995 Consensus Conference of the Canadian Cardiovascular Society on "Indications for and Access to Revascularization" recommended that Canadian centres with invasive cardiovascular facilities should participate in a national observational database that monitors the selection of patients, as well as evaluate outcomes. The Canadian Cardiovascular Society, the Heart and Stroke Foundation of Canada, and Health Canada with IBM as a partner, initiated a process to identify factors influencing the development of the Canadian Cardiovascular Information Network. IBM's "Business Discovery Methodology" was adapted for health care. Structured interviews with representatives of health organizations, cardiovascular databases and research institutes were conducted across Canada, followed by a workshop to identify goals, issues and challenges. Participants identified goals for a cardiovascular database (eg, evidence-based decision-making), project related issues (eg, respecting the integrity of existing databases) and health care related issues (eg, cardiac waiting lists). Challenges included initial mistrust between representatives of provincial cardiovascular databases and national agencies, and a lack of sustained funding. A Project Team was formed to address 'cardiac waiting lists'. Analysis of Alberta and Ontario data identified differences in definitions, such as when the waiting time for bypass surgery began, that impeded detailed comparisons. Development of a centralized national database was not feasible at this time for political, technical and financial reasons. However, provincial cardiovascular database representatives agreed to work together and to share aggregate data and analyses. A first step toward developing a national surveillance system for cardiovascular services will be achieving consensus about standardizing data definitions. This process will require sustained funding.

Improvement of apparently fixed pulmonary hypertension with cardiac resynchronization therapy

Many patients with advanced heart failure are ineligible for cardiac transplantation because of fixed pulmonary arterial hypertension. Cardiac resynchronization therapy, by stimulating the right atrium, and right and left ventricles, is a new therapy that effectively palliates symptoms in patients with heart failure. Cardiac resynchronization therapy increases cardiac output and decreases pulmonary capillary wedge pressure, thus partially reversing hemodynamic abnormalities that lead to secondary pulmonary hypertension in many heart failure patients. We describe a patient whose previously fixed pulmonary hypertension improved to the point that she was once again considered eligible for cardiac transplantation.

Defective auditory interhemispheric transfer in a patient with a PAX6 mutation

Heterozygous PAX6 mutation is associated with an absent or hypoplastic anterior commissure and a reduction in the area of the corpus callosum. The authors found deficient auditory interhemispheric transfer in a 53-year-old woman with a PAX6 mutation who had an absent anterior commissure but normal callosal volume.

Improved Early Survival with the Total Artificial Heart

We report our experience with the total artificial heart (TAH) to determine if outcomes have improved. Thirty-one patients received the TAH as a bridge to transplant and were divided into the two groups A (eighteen implanted in the first eight years) and B (thirteen implanted in the last eight years). Changes in management included immediate sternal closure, early extubation, delayed transplant listing, early rehabilitation, and measurement of preformed antibodies. The infection rate in B was lower than in A, both during support (31% versus 39%) and following transplant (38% versus 72%), and rejection was lower in B than in A (0% versus 44%). There was no difference in neurological events between groups; however, reopening was more frequent in B (61% versus 28%). Hospital survival increased from 61% in A to 85% in B; however, this was not statistically significant. We hypothesize that this improvement was likely due to changes in patient management.

Ventricular Assist Devices as a Bridge to Cardiac Transplantation: The Ottawa Experience

This article reports our experience with ventricular assist devices (VADs) as a bridge to cardiac transplantation. From 1991 to 2003, a total of 42 patients received a Thoratec VAD (Thoratec Laboratories Corporation Inc., Pleasanton, CA, U.S.A.) (Group T) and 12 patients received a Novacor VAD (WorldHeart Corporation, Ottawa, Canada) (Group N). Thirty Thoratec patients were transplanted compared to six in the Novacor group. Four more Novacor patients are still supported. Of the transplanted patients, 87% survived to hospital discharge in Group T and 67% in Group N. Infections affected 29% and 50% of Group T patients during support and post-transplantation, respectively, compared to 25% and 0%, respectively, in Group N. Neurologic complications affected 33% of patients in each group during support. Reopening rates for bleeding during support were 45% and 42% in Groups T and N, respectively. There were no significant differences in outcomes between the two groups. Our study demonstrated the effectiveness of VADs in bridging mortally ill cardiac patients to successful heart transplantation.

Heart Transplantation at the Ottawa Heart Institute: Comparison with Canadian and International Results

Heart transplantation has been carried out in 340 patients in Ottawa, including seventy-one who required mechanical circulatory support as a bridge to transplant. Survival in Ottawa was compared with other Canadian centers based on data from the Canadian Organ Replacement Register up to the year 2000 and with the International Society of Heart and Lung Transplantation (ISHLT) registry 2001. For survival analysis, the number of adult patients at risk at year 0 was 303 (87 transplanted from 1985 to 1990, 105 from 1990 to 1994, and 111 from 1995 to 2000). The Statistical Analysis System (SAS) life test procedure was used. Survival was not adjusted for comorbidities or heart failure class. For the year of transplant 1985-1989, one-, five-, and ten-year patient survival in Ottawa was 83%, 70%, and 60%, respectively, compared to 82%, 71%, and 54%, respectively, for Canada (Wilcoxon test, P = 0.71), and compared to one- and five-year survival for ISHLT from 1980 to 1987 at 76% and 60%, respectively. For 1990-1994, one-, five-, and ten-year patient survival in Ottawa was 88%, 81%, and 74%, respectively, compared to 80%, 71%, and 61%, respectively, for Canada (P = 0.05), and compared to one- and five-year survival for ISHLT from 1998 to 1992 at 80% and 68%, respectively. For 1995-2000, one- and five-year patient survival in Ottawa was 90% and 82%, respectively, compared to 85% and 76%, respectively, for Canada (P = 0.09), and compared to one- and five-year survival for ISHLT from 1993 to 1996 at 82% and 68%, respectively. Survival after heart transplantation in Ottawa compares favorably with Canadian and international data.

Positron emission tomography: a study of PET test-related anxiety

The objective of this study was to determine whether sending an information pamphlet to patients scheduled for a PET test two weeks prior to the appointment date significantly reduced patient anxiety and increased patient knowledge about the test. This study was conducted as a randomized controlled trial in which patients were randomly allocated to receive a mailed information pamphlet (intervention) or no mailed pamphlet two weeks prior to the appointment (usual care). The results of this study suggested that sending information pamphlets to patients scheduled for PET scans did not decrease pre-test levels of patient anxiety or result in increased patient knowledge about test preparation and procedures.

Herpes simplex encephalitis. A study of seven patients and their immunological response prior to routine acyclovir treatment

OBJECTIVES

A retrospective study on cerebrospinal fluid (CSF) samples was made possible by access to a large CSF bank, which has been supplemented by the well characterised prior collection of CSF from patients with Herpes simplex encephalitis (including serial samples from some patients and kindly donated by Professor Maurice Longson, Manchester). These samples are of particular interest because they were collected prior to the routine administration of acyclovir.

METHODS

Although an earlier study had shown that there was indeed a correlation between higher titres of antibody and a better outcome, the data did not emerge with statistical significance. The current study was based upon an improved method, which demonstrates the antigen-specific clonality of the immune response.

RESULTS

The primitive polyclonal anamnestic response was contrasted with the strong antigen-specific response, which was manifested by a monoclonal pattern in some patients. A clear distinction emerged between two sub-groups of patients on the basis of these findings, which showed a statistically significant (P<0.03) correlation with outcome.

CONCLUSIONS

This has allowed us to further support the hypothesis that a strong immunological response has positive prognostic value during the course of the disease.

Menstrual cycle effects on hypothalamic dopamine receptor function in women with a history of puerperal bipolar disorder

Neuroendocrine challenge tests of hypothalamic dopamine receptor function in the early postpartum period suggest that the sensitivity of these receptors is increased in women with a history of bipolar disorder after childbirth. We tested the hypothesis that, in women predisposed to bipolar disorder in the puerperium, hypothalamic dopamine receptor function is more sensitive to changes in circulating ovarian hormone concentrations than in women without such histories. Eight fully recovered and drug-free women who had had at least one episode of bipolar illness following childbirth were compared with nine normal controls. Growth hormone (GH) responses to apomorphine (APO 0.005 mg s.c.) were measured in the early follicular phase, when plasma concentrations of ovarian hormones are low, and in the mid-luteal phase, when they are relatively high. The recovered bipolar subjects and the controls did not differ from each other in their follicular and midluteal oestrogen and progesterone concentrations. In the midluteal phase, both groups had increased oestrogen and progesterone levels. The recovered bipolar subjects did not differ from controls in baseline concentrations of GH in either of the menstrual phases. The APO-GH responses of the two groups did not differ in the follicular phase, but in the midluteal phase, when female sex steroids are relatively increased, the recovered group had significantly enhanced APO-GH responses [MANOVA for repeated measures: (i) area under the curve, group by phase effect: p < 0.04; (ii) GH peak rise after APO, group by phase effect: p < 0.056] and the responses were not related to concurrent measures of mood. The results of this small study of women predisposed to bipolar disorder in the puerperium shows an increased dopaminergic receptor sensitivity in the luteal phase of the menstrual cycle. It suggests that their dopaminergic systems have increased sensitivity to changes in circulating female sex steroids. This may be aetiologically relevant to the pathogenesis of puerperal bipolar disorder.

Mechanical circulatory support for adolescent patients: the Ottawa Heart Institute experience

BACKGROUND

Mechanical circulatory support devices may be used for patients with end-stage heart failure for bridging either to cardiac transplant or to recovery of the native heart. While less common in adolescents, fulminant heart failure may be rapidly fatal in these patients unless circulatory support can be instituted.

OBJECTIVES

To assess the outcomes and the utility of mechanical circulatory assist devices for children.

METHODS

A retrospective review of pediatric patients (18 years of age or younger) who underwent circulatory support at the Ottawa Heart Institute, Ottawa, Ontario, from 1992 to 2001 was performed using chart audits.

RESULTS

Seven patients (four boys, three girls) with a mean age of 14.9 +/- 0.9 years were supported with Thoratec ventricular assist devices (n=6) or a CardioWest total artificial heart (n=1). Preoperatively, the cardiac index was 1.64 +/- 0.2 L/min/m2 on one or two inotropes with ejection fractions of 11 +/- 2.2%. Mean duration of circulatory support was 59.3 +/- 17.2 days with a hospital length of stay of 89.6 +/- 12.8 days. All seven patients underwent successful transplantation and were discharged home.

CONCLUSIONS

Pediatric patients with fulminant heart failure may be bridged to cardiac transplant successfully with mechanical circulatory support devices.

Prognostic use of cardiac troponin T and troponin I in patients with heart failure

BACKGROUND

Troponin T (cTnT) and troponin I (cTnI) are present in the sera of some heart failure (HF) patients and have potential importance as prognostic markers.

OBJECTIVE

To prospectively evaluate the prognostic value of cTnT and cTnI in well-characterized HF patients and clarify their relationship to other clinical markers of HF severity.

METHODS

cTnT and cTnI were measured in 78 HF patients (45 inpatients, 33 outpatients) who were followed up prospectively for 12 months.

RESULTS

Plasma cTnT (> or =0.02 ng/mL) and cTnI (> or =0.3 ng/mL) were detected in 51% and 46% of patients, respectively. These patients were more likely to be inpatients (70% versus 45% for cTnT, 75% versus 43% for cTnI, P<0.05 for both), have a higher plasma creatinine (153 versus 119 micromol/L for cTnT; 157 versus 118 micromol/L for cTnI, P<0.05) and lower plasma sodium (134 versus 138 mmol/L for both, P<0.05). At 12 months, they were more likely to have died or undergone cardiac transplantation (41% versus 14%, P=0.01 for cTnT; 43% versus 15%, P=0.004 for cTnI). After adjustment for New York Heart Association class, plasma sodium and inpatient status, a significant association with events was still evident for both troponins.

CONCLUSIONS

Both cTnT and cTnI are strongly associated with other clinical indicators of HF severity and remain independent predictors of prognosis after adjustment for these factors. These results indicate a potential role for cTnT and cTnI in the clinical management of HF patients.

Giant cell myocarditis: clinical presentation, bridge to transplantation with mechanical circulatory support, and long-term outcome

BACKGROUND

The multicenter Giant Cell Myocarditis Registry recorded 64 cases from 36 centers before 1996. The median transplant-free survival of 30 patients without immunosuppression was 3 months. Of 34 patients who received heart transplantations, 9 experienced recurrence of giant cell myocarditis in their transplanted hearts and 1 patient died.

METHODS

We reviewed our experience in 340 heart transplantations since 1984. Unexpected giant cell myocarditis was found in the explanted hearts of 7 patients (6 men and 1 female, aged 18-65 years).

RESULTS

The duration from the onset of symptoms to assist-device implant or transplantation ranged from 11 days to 9 years, whereas the time interval from referral or deterioration ranged from 2 days to 4 months. Four patients required mechanical circulatory support before surgery (total artificial hearts in 2 and left ventricular assist devices in 2), and 3 patients required inotropic drugs. Six patients are alive with no sign of recurrent giant cell myocarditis at 12 to 113 months after surgery. One patient died suddenly 75 months after surgery, and autopsy showed severe graft vascular disease with no recurrence of giant cell myocarditis. Surveillance, right ventricular endomyocardial biopsy specimens showed recurrent asymptomatic giant cell myocarditis in 3 patients at 5 to 13 months after surgery, and found recurrence in 1 patient 30 months after surgery. This patient received augmented immunosuppression.

CONCLUSIONS

Giant cell myocarditis often is not diagnosed before transplantation. It can present as dilated cardiomyopathy with late deterioration, or it can present with rapid hemodynamic deterioration. In our experience, these patients can be bridged successfully to transplant with mechanical circulatory assist. Giant cell myocarditis may recur after transplantation but may respond to augmented immunosuppression.

The use of ultrasound to demonstrate small bowel polyps in a patient with Peutz-Jeghers syndrome

A 21-year-old woman presented to the accident and emergency department with a 2-day history of lower abdominal pain. Her lips had the stigma of melanosis. Previously, she had received a diagnosis of Peutz-Jeghers syndrome, although no polyps had been detected in small and large bowel barium studies performed approximately 8 years before. Clinically, the patient had mild deep lower abdominal tenderness, and a mass was palpable in the suprapubic region. Urgent ultrasound showed ileoileal intussusception and small polyps in the lumen of the small bowel. At laparotomy, ileoileal intussusception was confirmed. It was not possible to reduce it because of nonviable small bowel, so 20 cm of the ileum, including the intussusception, was excised. After this, intraoperative enteroscopy was performed, showing further polyps in the small bowel distal and proximal to the intussusception, which were excised locally. Only a few reports in the literature describe ultrasound used to diagnose to condition. Intraoperative enteroscopy has been recommended as the treatment of choice because it allows identification of polyps that previously would have been missed.

Positional down beating nystagmus in 50 patients: cerebellar disorders and possible anterior semicircular canalithiasis

OBJECTIVES

To clarify the clinical significance of positional down beat nystagmus (pDBN).

METHODS

A discussion of the neuro-otological findings in 50 consecutive patients with pDBN.

RESULTS

In 38 patients there was evidence of CNS disease (central group) but in 12 there was not (idiopathic group). In the CNS group, presenting symptoms were gait, speech, and autonomic dysfunction whereas in the idiopathic group patients mostly reported positional vertigo. The main neurological and oculomotor signs in the CNS group were explained by cerebellar dysfunction, including 13 patients with multiple system atrophy. In patients with multiple system atrophy with a prominent extrapyramidal component, the presence of pDBN was helpful in the differential diagnosis of atypical parkinsonism. No patient with pDBN had the Arnold-Chiari malformation, a common cause of constant down beat nystagmus (DBN). In the idiopathic group, the pDBN had characteristics which suggested a peripheral labyrinthine disorder: vertigo, adaptation, and habituation. In six patients an additional torsional component was found (concurrently with the pDBN in three). Features unusual for peripheral disorder were: bilateral positive Dix-Hallpike manoeuvre in nine of 12 patients and selective provocation by the straight head-hanging manoeuvre in two.

CONCLUSION

It is argued that some patients with idiopathic pDBN have benign paroxysmal positional vertigo (BPPV) with lithiasis of the anterior canal. The torsional component may be weak, because of the predominantly sagittal orientation of the anterior canal, and may not be readily seen clinically. Nystagmus provocation by bilateral Dix-Hallpike and straight head-hanging may be explained by the vertical upwards orientation of the ampullary segment of the anterior canal in the normal upright head position. Such orientation makes right-left specificity with the Dix-Hallpike manoeuvre less important than for posterior canal BPPV. This orientation requires a further downwards movement of the head, often achieved with the straight head-hanging position, to provoke migration of the canaliths. The straight head-hanging manoeuvre should be carried out in all patients with a history of positional vertigo and a negative Dix-Hallpike manoeuvre.

Symptoms, disability and handicap in unilateral peripheral vestibular disorders. Effects of early presentation and initiation of balance exercises

The aim of this study was to obtain a profile of disability and handicap in patients with unilateral peripheral vestibular disorders presenting to a specialist tertiary care unit. Two validated questionnaires were sent to patients who had a unilateral peripheral vestibular disorder as defined by strict criteria. Some patients still suffered moderate handicap and disability 5 years after the initial symptoms related to a unilateral vestibular disorder, although the duration of symptoms (onset to questionnaire completion) did not correlate with severity of disability and handicap, as judged by questionnaire scores. However, patients presenting to the unit within 6 months of onset of vertigo commenced balance exercises significantly earlier and had significantly lower disability scores than patients presenting later. A high proportion of non-compliance with, and delay in initiation of, vestibular rehabilitation exercises was noted in the total patient sample, while compliance with, and early initiation of, Cooksey Cawthorne exercises were significantly correlated with low disability and questionnaire scores. These findings suggest that early referral to a specialist balance unit for patients with persistent dizziness is associated with better outcome.