Canadian Hypertension Education Program. The 2007 Canadian Hypertension Education Program recommendations: the scientific summary - an annual update

Antihypertensive effects of new dihydropyridine derivatives on phenylephrine-raised blood pressure in rats

Changes in the substitutions at C-3 and C-5 positions of 4-(1-methyl-5-nitro-2-imidazolyl) dihydropyridine analogs of nifedipine have led to changes in potency of the compounds. The objective of the present study was to examine the hypotensive effects of 5 newly synthesized dihydropyridine derivatives of nifedipine in rats with phenylephrine-raised blood pressure. Anesthetized Sprague-Dawley rats were randomly assigned to 19 groups of 7 animals each. Control group received the vehicle dimethylsulfoxide (0.05 mL), 3 groups were given nifedipine at 100, 300, or 1000 μg/kg, and 5 other groups each composed of 3 subgroups administered one of the 5 new dihydropyridine compound at 100, 300, or 1000 μg/kg. All animals were initially infused with 20 µg/kg/min phenylephrine for 45 min, and were then given a bolus of either dimethylsulfoxide, nifedipine, or new dihydropyridine compounds 20 min after the commencement of phenylephrine infusion. Blood pressure and heart rate (HR) of the animals were measured before and at the end of phenylephrine infusion, or 25 min after injection of vehicle or compounds. Compared to dimethylsulfoxide, nifedipine, and new 1, 4-dihydropyridine derivatives caused significant reductions in MBP. Moreover, cyclohexyl propyl, phenyl butyl, and cyclohexyl methyl analogs of 1, 4-dihydro-2,6-dimethyl-4-(1-methyl-5-nitro-2-imidazoyl)-3,5-pyridinedicarboxylase at 100 μg/kg, phenyl butyl, and cyclohexyl methyl analogs at 300 μg/kg, and cyclohexyl methyl analogs at 1000 μg/kg reduced MBP similar to nifedipine. There was no significant difference between HR of all groups before and after administration of the compounds. The findings indicated that changes in substitution at C-3 and C-5 positions of 2-(1-methyl-5-nitro-2-imidazolyl) dihydropyridine analogs of nifedipine were associated with changes in hypotensive activity of the compounds.

Rheumatologist and Primary Care Management of Cardiovascular Disease Risk in Rheumatoid Arthritis: Patient and Provider Perspectives

OBJECTIVE

Despite increased cardiovascular disease (CVD) risk, rheumatoid arthritis (RA) patients often lack CVD preventive care. We examined CVD preventive care processes from RA patient and provider perspectives to develop a process map for identifying targets for future interventions to improve CVD preventive care.

METHODS

Thirty-one participants (15 patients, 7 rheumatologists, and 9 primary care physicians [PCPs]) participated in interviews that were coded using NVivo software and analyzed using grounded theory techniques.

RESULTS

Patients and providers reported that receipt of preventive care depends upon identifying and acting on risk factors, although most noted that both processes rarely occurred. Engagement in these processes was influenced by various provider-, system-, visit-, and patient-related conditions, such as patient activation or patients' knowledge about their risk. While nearly half of patients and PCPs were unaware of RA-CVD risk, all rheumatologists were aware of risk. Rheumatologists reported not systematically identifying risk factors, or, if identified, they described communicating about CVD risk factors via clinic notes to PCPs instead of acting directly due to perceived role boundaries. PCPs suggested that scheduling PCP visits could improve CVD risk management, and all participants viewed comanagement positively.

CONCLUSION

Findings from this study illustrate important gaps and opportunities to support identifying and acting on CVD risk factors in RA patients from the provider, system, visit, and patient levels. Future work should investigate professional role support through improved guidelines, patient activation, and system-based RA-CVD preventive care strategies.

Dihydropyridine calcium channel blockers and cardiovascular outcomes in elderly patients: a population-based study

BACKGROUND

Dihydropyridine calcium channel blockers are widely used for the treatment of hypertension and angina. Despite safety concerns associated with short-acting agents, increasing evidence supports the safety of long-acting dihydropyridines. Although amlodipine is the best studied of these, there are few studies comparing it with nifedipine.

OBJECTIVE

To examine the association between hospitalization for acute coronary syndromes and treatment with amlodipine or extended-release nifedipine in patients 65 years of age and older. The primary objective was a composite of hospital admission for angina or acute myocardial infarction.

METHODS

The present population-based, retrospective cohort study used linked health care databases from Ontario. Propensity scores were used to identify highly similar patients started on amlodipine or extended-release nifedipine between April 1997 and March 2002. Time-to-event analysis was conducted using Cox proportional hazards models.

RESULTS

The analysis included 24,190 patients (44% male; mean age 75 years) treated with amlodipine or extended-release nifedipine (n=12,095 each). The number of patients reaching the primary end point was 362 (3%) and 294 (2.4%) in the amlodipine and nifedipine groups, respectively. The groups were similar in a large number of demographic and clinical characteristics. No significant differences were observed among users of extended-release nifedipine (adjusted hazard ratio 0.91, 95% CI 0.74 to 1.13) relative to amlodipine.

CONCLUSIONS

These findings suggest that amlodipine and extended-release nifedipine are not associated with differential rates of acute coronary events in older patients.

High-normal blood pressure, impaired glucose regulation and metabolic syndrome have variable impact on central artery stiffness

AIMS

This cross-sectional study compared carotid artery stiffness in metabolic syndrome (MS) subjects with high-normal blood pressure (HNBP) and/or impaired glucose regulation.

METHODS

Eighty-nine subjects (40M and 49F, 53.5+/-9.3 years) with either HNBP, impaired glucose regulation, or both were studied. The following measurements were included: risk factors for MS (waist circumference, blood pressure (BP), glucose, triglycerides and high-density lipoprotein (HDL) cholesterol), and carotid artery stiffness (Doppler ultrasound).

RESULTS

Forty-four subjects (20M and 24F) were classified as without MS (MS-) and 45 subjects (20M and 25F) as with MS (MS+). As expected, each component of MS was different between the groups (all p<0.05). Arterial distensibility in MS+ was significantly lower than in MS- (0.152+/-0.010 vs. 0.181+/-0.0091/mmHg x 10(-2), p<0.05), while beta stiffness index was not different between the two groups (12.3+/-1.1 vs. 10.5+/-1.1 AU, p=0.115). Multivariate analysis revealed that carotid artery stiffness was independently associated with resting HR together with age (both p<0.05).

CONCLUSIONS

These results show that, in subjects with HNBP and/or impaired glucose regulation: (1) the presence of MS decreases arterial distensibility of the carotid artery but do not increase beta stiffness index and (2) the presence of MS dose not synergistically increase carotid artery stiffness.

Recording blood pressure readings in elderly patients' charts: what patient and physician characteristics make it more likely?

OBJECTIVE

To identify patient and physician characteristics associated with family physicians recording blood pressure (BP) measurements in the medical charts of their elderly patients.

DESIGN

Retrospective review of patients' charts during a 12-month period and baseline questionnaire on the sociodemographic and practice characteristics of family physicians participating in the Community Hypertension Assessment Trial. The chart review collected data on patients' demographics, cardiovascular risk factors, antihypertensive medications, number of visits to family physicians, and number of BP readings recorded.

SETTING

Non-academic family practices in Hamilton and Ottawa, Ont.

PARTICIPANTS

Data were abstracted from the charts of 55 randomly selected regular elderly patients (65 years old and older) from each of 28 participating family practices (N = 1540 charts).

MAIN OUTCOME MEASURE

Number of recordings of BP measurements in medical charts during a 12-month period.

RESULTS

About 16% (241/1540) of elderly patients had not had their BP recorded in their charts during the 12-month review period. Among this 16%, almost half (47%, 114/241) had not had a BP measurement recorded during the previous 24 months. Multivariate analysis indicated that the likelihood of BP recording increased with the number of visits made to family physicians and was greater among patients taking antihypertensive medications or diagnosed with hypertension. Physicians who had more recently graduated from medical school (< or = 24 years) were more likely to record BP measurements.

CONCLUSION

Hypertension guidelines recommend that, for patients at risk, BP be measured and recorded at each office visit. Although more than 84% of older patients had at least 1 BP reading documented in their charts, patients who were already diagnosed with hypertension or who made frequent visits to the office were more likely to have their BP measured and recorded. A more systematic approach to monitoring elderly patients who visit their family physicians less frequently or who are not currently diagnosed with hypertension is needed.