Patient-years In Patients Research Articles

Prognostic significance of left ventricular diastolic dysfunction in essential hypertension

ObjectivesWe sought to assess the prognostic value of alterations in left ventricular (LV) diastolic function in patients with essential hypertension. BackgroundAlterations in LV diastolic function are frequent in patients with hypertension, even in the absence of LV hypertrophy, but their prognostic significance has never been investigated. MethodsIn the setting of the Progetto Ipertensione Umbria Monitoraggio Ambulatoriale (PIUMA) study, we followed, for up to 11 years (mean: 4.4 years), 1,839 Caucasian hypertensive patients (50 ± 12 years, 53% men, blood pressure (BP) 156/98 mm Hg) without previous cardiovascular events, who underwent Doppler echocardiography and 24-h BP monitoring before therapy. The early/atrial (E/A) mitral flow velocity ratio was calculated and corrected for age and heart rate (HR). ResultsDuring follow-up, there were 164 major cardiovascular events (2.04 per 100 patient-years). The incidence of cardiovascular events was 2.47 and 1.65 per 100 patient-years in patients with an age- and HR-adjusted E/A ratio below (n = 919) and above (n = 920) the median value, respectively (p < 0.005 by the log-rank test). In Cox analysis, controlling for age, gender, diabetes, cholesterol, smoking, LV mass and 24-h systolic BP (all p < 0.05), a low age- and HR-adjusted E/A ratio conferred an increased risk of cardiovascular events (odds ratio 1.57, 95% confidence interval [CI] 1.11 to 2.18, p < 0.01). A 21% excess risk was found for each 0.3 decrease of the adjusted E/A ratio (95% CI from +2% to +43%; p = 0.03). ConclusionsImpaired LV early diastolic relaxation, detected by pulsed Doppler echocardiography, identifies hypertensive patients at increased cardiovascular risk. Such association is independent of LV mass and ambulatory BP.

Parathyroidectomy in Patients on Renal Replacement Therapy

Secondary hyperparathyroidism is a frequent complication of long-term dialysis treatment, and despite recent advances in medical therapy, surgical parathyroidectomy (PTx) is necessary in a considerable number of uremic patients. A prevalence of PTx of 22% was reported in Europe in 1988 in patients on dialysis from 10 to 15 yr, but no large-scale epidemiologic study has been published since then. The aim of the study was to evaluate the prevalence, incidence, and risk factors for PTx in patients on renal replacement therapy (RRT) in Lombardy and to determine whether the incidence has changed over time. The study involved 14,180 patients included in the Lombardy Registry of Dialysis and Transplantation who received RRT for end-stage renal disease (ESRD) between 1983 and 1996. Cox-proportional hazards regression models were used to evaluate the risk factors of PTx, the explanatory covariates being age on admission to RRT, gender, underlying renal disease (nondiabetic or diabetic nephropathy), and dialysis modality (peritoneal dialysis or hemodialysis). The prevalence of PTx in the 7371 ERSD patients who were alive on December 31, 1996, was 5.5% and increased with the duration of RRT (9.2% after 10 to 15 yr, 20.8% after 16 to 20 yr). Similarly, the incidence of PTx increased from 3.3 per 1000 patient-years in patients who had been on RRT for <5 yr to 30 per 1000 patient-years in those receiving RRT for >10 yr. The Cox regression models showed that the relative risk for PTx was significantly higher in women and lower in elderly and diabetic patients. The relative risk for PTx (adjusted for gender, age, and nephropathy) was higher in the patients on peritoneal dialysis than in those on hemodialysis and decreased after transplantation. During the course of a follow-up of 7 yr, the incidence of PTx in patients who started RRT between 1990 and 1992 was no different from that observed in patients who started RRT between 1983 and 1985. In conclusion, the prevalence and incidence of PTx in patients receiving RRT in Lombardy is lower than that in Europe and Italy as a whole, as reported by the 1988 European Dialysis and Transplantation Association Registry; its frequency has not changed significantly during the past few years. The need for PTx decreases markedly after successful transplantation. The epidemiologic finding that the rate of PTx is greater in women, young patients, and individuals who do not have diabetes suggests the need for a more aggressive medical treatment of secondary hyperparathyroidism particularly in such patients.

Cost-effectiveness of self-managed anticoagulant therapy in Germany.

In this study, the cost-effectiveness of anticoagulation self-management--which is now established in Germany--was compared with the conventional method of monitoring oral anticoagulant therapy by the patient's family physician or by a specialist. Costs were determined based on the usual conditions in Germany such as frequency of testing and control testing, scope of the tests, and diagnostic and therapeutic standards for thromboembolic or bleeding complications. In addition to direct monitoring costs, we determined the costs for treating minor and serious complications and used them to calculate overall therapy costs. The incidence of complications was estimated based on the results of more recent studies. The only costs considered in this study were those covered by the primary cost carrier--the government-controlled health insurance funds--and included outpatient visits and, in cases of serious complications, acute inpatient treatment and rehabilitation. It was shown that the costs to treat minor complications only slightly affected annual, overall treatment costs. The potential reduction in incidences of serious bleeding and thromboembolic complications due to anticoagulation self-management--which is independent of the indication for oral anticoagulation--reduced overall therapy costs from DM 2,061.48/patient-year for conventional therapeutic methods to DM 1,342.46/patient-year for patients under self-management of anticoagulation.

Chronic recurrent stress due to panic disorder does not precipitate Graves' disease.

A role of psychic stress in precipitating hyperthyroid Graves' disease has been suggested, but the evidence in support of this pathogenetic mechanism is conflicting. In this study we investigated the possible occurrence of Graves' disease in patients with panic disorder, a psychiatric condition characterized by recurrent endogenous stress. The study group included 87 consecutive patients suffering from panic disorder since 1 to 30 years: 17 males (mean age 31.3, range 26-43 years) and 70 females (mean age 37.6, range 15-73 years). Two hundred and sixty-two normal subjects with no present or past history of psychiatric disorder served as controls. Patients were submitted to a full evaluation of the thyroid that included physical examination, assays for free thyroid hormones, TSH, thyroglobulin (TgAb), thyroperoxidase (TPOAb) and TSH receptor (TRAb) antibodies, and thyroid echography. The prevalence of circulating TgAb and/or TPOAb in patients with panic disorder did not differ from that in the control group. Twelve patients with panic disorder (13.7%) had circulating TgAb and/or TPOAb, but none had TRAb. Three out of 12 patients with thyroid antibodies, indicating a genetic susceptibility to autoimmune thyroid disease, had a family history of clinical thyroid autoimmunity, and 4 of them had a hypoechogenic pattern of the thyroid at ultrasound suggesting autoimmune thyroiditis. None of the patients with panic disorder had a previous history of hyperthyroidism. On examination, clinical hyperthyroidism or endocrine ophthalmopathy were not found in any of them. A small goiter was appreciated by palpation in 16 patients (18.3%). Free thyroid hormones and TSH were within the normal range in all patients but one: a 55-year old lady with normal serum free thyroid hormones and undetectable TSH. During an 18-month follow-up she did not develop hyperthyroidism and her TSH spontaneously returned in the normal range. Considering the individual duration of panic disorder, evidence for previous or present Graves' hyperthyroidism was not found for a total of 478 patient-years of exposure to recurrent endogenous stress in the whole study group, and for a total of 39 patient-years in patients with a genetic susceptibility to autoimmune thyroid disease. In conclusion, we found that recurrent endogenous stress did not precipitate Graves' hyperthyroidism in a series of 87 patients with panic disorder, encompassing a total of 478 patient-years of exposure to stress. Failure to activate the hypothalamic-pituitary-adrenal axis by endogenous stress due to panic disorder as opposed to exogenous stress due to life-events might explain why panic disorder does not precipitate Graves' hyperthyroidism.

Blood pressure control and recurrence of hypertensive brain hemorrhage.

Recent studies have demonstrated that recurrence of hypertensive brain hemorrhage (HBH) is not uncommon. However, risk factors for the recurrence of HBH have not been evaluated systematically. We analyzed 74 patients with HBH who were admitted to our clinic and followed up as outpatients for a mean of 2.8 years. Blood pressure (BP) and other clinical features were compared between the groups of patients with and without rebleeding. We determined the recurrence rate of HBH in relation to BP. Diastolic BP was significantly higher in the recurrence group than in the nonrecurrence group (88+/-8 versus 82+/-7 mm Hg; P=0.04). Systolic BP and other clinical variables were not different between the groups. The recurrence rate was 10.0% per patient-year in patients with diastolic BP >90 mm Hg and <1.5% in those with lower diastolic BP (P<0.001). No patients with diastolic BP <70 mm Hg experienced rebleeding. Higher diastolic BP was related to an increased rate of rebleeding. Diastolic BP >90 mm Hg may be regarded as a factor predictive of the recurrence of HBH.

The use and cost of HIV service provision in England in 1996. National Prospective Monitoring System (NPMS) Steering Group and NPMS Working Party on Costs.

The aim of the study was to measure the use and estimate the cost of HIV service provision in England. Standardised activity and case-severity data were collected prospectively in 10 English HIV clinics (5 London and 5 non-London sites) for the periods 1 January 1996 to 30 June 1996 and 1 July 1996 to 31 December 1996 and linked to unit cost data. In total, 5440 patients with HIV infection attended during the first 6 months and 5708 during the second 6 months in 1996. The mean number of inpatient days per patient-year for patients with AIDS was 19.7 [95% confidence interval (CI): 13.7 to 25.7] for January to June and 20.8 (95% CI: 15.3 to 26.4) for July to December 1996. The mean number of outpatient visits for asymptomatic patients with HIV infection was 14.8 (95% CI: 11.9 to 17.6) and 13.3 (95% CI: 10.8 to 15.7) for the respective periods and 16.1 (95% CI: 13.21 to 18.97) and 15.7 (95% CI: 11.2 to 20.2), respectively, for patients with symptomatic non-AIDS (i.e. symptomatic patients with HIV infection but without AIDS-defining conditions). Substantial centre-to-centre variation was observed, suggesting that many clinics can continue the shift from an inpatient- to an outpatient-based service. Cost estimates per patient-year for HIV service provision for 1996 varied from 4695 Pounds (95% CI: 3769 Pounds to 5648 Pounds) for asymptomatic patients, to 7605 Pounds (95% CI: 6273 Pounds to 8909 Pounds) for symptomatic non-AIDS patients to 20,358 Pounds (95% CI: 17,681 Pounds to 23,206 Pounds) for patients with AIDS. Different combinations of antiretroviral therapy affect the cost estimates of HIV service provision differently. Anticipated reduction in inpatient-related activity through the increased use of combination antiretroviral therapy will further shift service provision from an inpatient- to outpatient-based service and reduce costs per patient-year. The extent and duration of such effects are currently unknown. The long term effects of combination treatment on the morbidity and mortality patterns of individuals infected with HIV are also currently unknown, as are their implications on the use and cost of HIV service provision. Multicentre databases like the National Prospective Monitoring System (NPMS) will provide healthcare professionals with information to improve existing services and anticipate the impact of new developments.

The use and cost of hospital services by London AIDS patients with different AIDS defining conditions.

Contracting for HIV service provision is now an established part of the National Health Service commissioning process. AIDS is a heterogeneous condition, comprising various opportunistic illnesses which require different services and which have different resource implications. This study describes the use of hospital services and associated costs for the management of different AIDS defining conditions. A retrospective case-notes analysis was performed, of 335 AIDS patients treated at St Mary's Hospital, London, between 1 January 1983 and 30 September 1989, as well as a costing exercise of 37 clinical departments to calculate HIV-related costs. Mean age at time of AIDS diagnosis for these predominantly homosexual men was 38 years. Use of services varied, as did associated costs-from 8163 pounds per patient-year for patients with Constitutional Disease to 42,124 pounds for those with Cytomegalovirus Disease Most diagnostic categories showed a shift over the study period from an in-patient- to an out-patient-based service. Patients diagnosed after 1987 had overall lower costs per patient-year compared with those diagnosed before 1987: whereas out-patient costs for most groups had increased, in-patient expenditure decreased. For most categories, in-patient care costs and out-patient drugs prescribed provided the greatest proportion of total costs. Average costs per in-patient day ranged from 334 pounds to 433 pounds, and average costs per out-patient visit ranged from 99 pounds to 411 pounds for different AIDS defining conditions. Different opportunistic illnesses of symptomatic HIV disease have different treatment and resource implications. Casemix will need to be taken into consideration when contracting for HIV services, including extra-contractual referrals.

The St. Jude Valve prosthesis: Analysis of the clinical results in 815 implants and the need for systemic anticoagulation

Between July 1979 and December 1984, 785 patients received 815 St. Jude Medical valve prostheses. Valve-related mortality in the follow-up period was due to thromboemholism in seven cases, anticoagulant-related hemorrhage in three and perivalvular leak in two. Freedom from valve-related death or reoperation at 3 years was 96.4% for aortic valve replacement and 98.3% for mitral valve replacement. The overall rate of thromboembolism was 2.6%/patient-year with warfarin, 9.2%/patient-year with antiplatelet medication and 15.6%/patient-year in patients with no anticoagulant therapy. One episode of thrombotic obstruction of a mitral valve, in a patient receiving no anticoagulant therapy, resulted in an occurrence rate of such obstruction of 0.22%/patient-year.Valve replacement with the St. Jude valve produced excellent clinical results, but long-term anticoagulation with warfarin was required to minimize thromboembolic complications. The use of antiplatelet agents alone provided inadequate protection.

Comparative study of primary tissue failure between porcine (Hancock and Carpentier-Edwards) and bovine pericardial (Ionescu-Shiley) bioprostheses in the aortic position at five- to nine-year follow-up

Retrospective follow-up data on 458 consecutive patients who received a Hancock, Carpentier-Edwards (C-E) or Ionescu-Shiley (I-S) bioprosthesis in the aortic valve position between April 1978 and December 1981 are reviewed. A total of 461 valves (184 Hancock, 131 C-E and 146 I-S) were available for study of the incidence of primary tissue valve failure after 5 to 9 years of follow-up. Cumulative follow-up was 1,016 patient-years for patients with Hancock valve, 688 for the C-E and 767 for the I-S group. Of the 397 prostheses at risk (154 Hancock, 120 C-E and 123 I-S), 36 instances of primary tissue valve failure occurred (12 Hancock, 7 C-E and 17 I-S). On an actuarial basis, the calculated probability of freedom from primary tissue valve failure was 88 ± 4% for the Hancock group, 87 ± 6% for the C-E and 51 ± 17% for the I-S at 9 years. The linear incidence of tissue valve failure was 1.2 failing valves per 100 patient-years for the Hancock group, 1 for the C-E and 2.2 for the I-S. In a cohort of patients older than 40 years of age at the time of valve replacement, the rate of freedom from primary failure was 98 ± 1%, 87 ± 9% and 44 ± 22% for the Hancock, C-E and I-S groups, respectively, at 9 years. Comparison of actuarial curves disclosed a meaningful difference between the pericardial valve and the Hancock and C-E porcine bioprostheses at 9-year follow-up. These data should have some bearing of practical import not only when comparing different types of bioprostheses, but especially when recommending the appropriate valve replacement for the individual patient.

Cardiac transplantation in patients over 50 years of age

Sixty-two patients underwent cardiac transplantation at the University of Arizona from March 1979 to March 1985. Thirteen patients (11 men and 2 women) were over 50 years of age at the time of transplantation and 49 were under the age of 50. The mean age (+/- SEM) of the patients over 50 was 53 +/- 1 years. Eight of these patients were treated with conventional immunosuppressive therapy (azathioprine, prednisone and rabbit antithymocyte globulin) and five, beginning in January 1983, were treated with cyclosporine, prednisone and rabbit antithymocyte globulin. Early mortality (0 to 90 days) was 16% in the group over 50 versus 18% for those under 50. The late mortality (greater than 90 days) was 36 and 33%, respectively. In both groups, rejection and infection were the principal causes of death. The incidence of infection was 1.9 +/- 0.5 episodes per patient in those patients over 50 and 1.9 +/- 0.4 in those under 50. The incidence of rejection was 1.3 episodes per patient-year in patients over 50 and 1.7 episodes per patient-year in those under 50. Actuarial survival at 1 year was 72 +/- 14% in the group over 50 and 66 +/- 7% in the group under 50 years of age. These data indicate that the results of cardiac transplantation for patients over 50 do not differ significantly from those for patients under 50. Therefore, it is concluded that a rigidly defined age criterion for cardiac transplant recipients is not acceptable. Each potential recipient must be evaluated in terms of individual risk and benefit from the procedure.