[Differential pressure as an independent factor of cardiovascular risk]

To confirm that high differential pressure (DP) supposes greater risk of ischaemic cardiopathy and to assess whether it is also an independent risk factor of suffering a cerebrovascular accident.

An analytical, observational, retrospective and longitudinal study with historic cohorts.

Urban population of about 18 000 inhabitants.

300 patients aged between 15 and 75 with hypertension of > or =2 years evolution, who have had their blood pressure taken by nurses 4 or more times (excluding casualty) and have not suffered a cardiovascular event (CVE), whether coronary accident, cerebrovascular accident or peripheral vasculopathy.

The history relating to cardiovascular risk was recorded: lipaemia, obesity, tobacco dependency, diabetes mellitus, left ventricular hypertrophy (LVH). These factors were considered present if their diagnosis preceded the CVE diagnosis. They were placed in 2 groups, depending on the degree of differential pressure: "high" if >60 mm Hg and "not high" if (3/4)60 mm Hg. They were analysed for intention to treat over 10 years, with the appearance or not of a CVE as a response variable.

300 participants (73.3% women), 150 exposed to risk and 150 not exposed. The initial analysis showed significant differences between the 2 groups for age (P<.0001), diabetes (P<.0001), and LVH (P<.001). After logistic regression, the OR of suffering LVH was 2.38 (95% CI, 1.19-4.74) in the group with high DP; the OR of ischaemic cardiopathy, 2.84 (95% CI, 1.16-6.96); and of cerebrovascular accident, 2.70 (95% CI, 1.09-6.68). There were no significant differences for peripheral arteriopathy.

DP was confirmed as an independent factor of cardiovascular risk and, despite the limitations of the study, it was pointed to as a possible independent factor of cerebrovascular risk.