Effects of ambient temperature, humidity, and other meteorological variables on hospital admissions for angina pectoris.

BACKGROUND: Seasonal peaks in cardiovascular disease incidence have been widely reported, suggesting weather has a role. DESIGN: The aim of our study was to determine the influence of climatic variables on angina pectoris hospital admissions. METHODS: We correlated the daily number of angina cases admitted to a western Sicilian hospital over a period of 12 years and local weather conditions (temperature, humidity, wind force and direction, precipitation, sunny hours and atmospheric pressure) on a day-to-day basis. A total of 2459 consecutive patients were admitted over the period 1987-1998 (1562 men, 867 women; M/F - 1:8). RESULTS: A seasonal variation was found with a noticeable winter peak. The results of Multivariate Poisson analysis showed a significant association between the daily number of angina hospital admission, temperature, and humidity. Significant incidence relative ratios (95% confidence intervals/measure unit) were, in males, 0.988 (0.980-0.996) (p = 0.004) for minimal temperature, 0.990 (0.984-0.996) (p = 0.001) for maximal humidity, and 1.002 (1.000-1.004) (p = 0.045) for minimal humidity. The corresponding values in females were 0.973 (0.951-0.995) (p < 0.017) for maximal temperature and 1.024 (1.001-1.048) (p = 0.037) for minimal temperature. CONCLUSIONS: Environmental temperature and humidity may play an important role in the pathogenesis of angina, although it seems different according to the gender. These data may help to understand the mechanisms that trigger ischemic events and to better organize hospital assistance throughout the year

Influence of climatic variables on acute myocardial infarction hospital admissions

BACKGROUND: Seasonal peaks in acute myocardial infarction (AMI) incidence have been widely reported. Weather has been postulated to be one of the elements at the basis of this association. The aim of our study was to determine the influence of seasonal variations and weather on AMI hospital admissions. METHODS: We correlated the daily number of AMI cases admitted to a western Sicily hospital over twelve years and weather conditions on a day-to-day basis. Information on temperature, humidity, wind force and direction, precipitation, sunny hours and atmospheric pressure was obtained from the local Birgi Air Force base. A total of 3918 consecutive patients were admitted with AMI over the period 1987-1998 (2822 men, 1096 women; M/F: 2,58). RESULTS AND CONCLUSIONS: A seasonal variation was found with a significant winter peak. The results of multivariate Poisson analysis show in both sexes a significant association as regards the incidence relative ratio between the daily number of AMI hospital admission and minimal daily temperature and maximal daily humidity. The incidence relative ratios (95% confidence intervals) were, in males, 0.95 (0.92-0.98) (p<0.001) as regards minimal temperature and 0.97 (0.94-0.99) (p=0.017) as regards maximal humidity. The corresponding values in females were respectively 0.91 (0.86-0.95) (p<0.001) and 0.94 (0.90-0.98) (p=0.009). Environmental temperature, and also humidity, may play an important role in the pathogenesis of AMI. These data may help in understanding the mechanisms whereby AMI events are triggered and in organizing better the assistance to ischemic patients throughout the yea

IN-HOSPITAL COMPLICATIONS OF ACUTE MYOCARDIAL INFARCTION IN HYPERTENSIVE SUBJECTS

BACKGROUND: Recent studies have shown a worse in-hospital outcome in hypertensive than in normotensive patients with acute myocardial infarction (AMI), which has been attributed to more frequent complications. The aim of this study was to investigate clinical patterns, risk factors, and in-hospital complications in hypertensive and normotensive patients with AMI. METHODS: Of 4994 consecutive patients with AMI admitted to the intensive care unit, hypertensive patients with first infarction (n = 915; mean age 68.8 +/- 11.4 years) and 915 gender- and age-matched normotensive subjects were retrospectively studied. RESULTS: In the univariate analysis, hypertensive subjects presented more frequently non-Q-wave infarction and ST segment depression than did normotensive subjects, even if hypertensive subjects more frequently had diabetes, dyslipidemia, renal failure, peripheral artery disease, cerebrovascular disease, and chronic obstructive pulmonary disease (P < .01 for all). Hypertensive subjects less frequently presented with cardiogenic shock (4.0% v 11.6%; P < .01), atrioventricular block (4.9% v 7.4%; P = .02), ventricular fibrillation (2.2% v 3.7%; P = .04), cardiac rupture (0.1% v 0.9%; P = .02), and ventricular thrombosis (0.5% v 1.5%; P < .03), and a higher frequency of paroxysmal atrial fibrillation (9.2 v 5.6%; P < .01). Mortality was significantly higher in patients with anterior versus inferior infarction, for all normotensive and hypertensive subjects (13.7% v 7.1%; P < .001), but mortality was remarkably higher in normotensive than in hypertensive subjects (17.8% v 6.2%; P < .001), regardless of infarction site (anterior, 11.2% v 4.1%; P < .001; inferior, 4.4% v 1.9%; P < .001). CONCLUSIONS: Hypertensive subjects with first AMI have a better in-hospital outcome than age- and gender-matched normotensive subjects, perhaps due to a less severe extension of the infarction area or to a different pathophysiologic mechanism