Disparity of Performance Measure by Door-to-Balloon Time Between a Rural and Urban Area for Management of Patients With ST-Segment Elevation Myocardial Infarction　- Insights From the Nationwide Japan Acute Myocardial Infarction Registry.

BACKGROUND

Although a door-to-balloon (D2B) time ≤90 min is recognized as a key indicator of timely reperfusion for patients with ST-segment elevation myocardial infarction (STEMI), it is unclear whether regional disparities in the prognostic value of D2B remain in contemporary Japan.

METHODS AND

RESULTS

We retrospectively analyzed 17,167 STEMI patients (mean [±SD] age 68±13 years, 77.6% male) undergoing primary percutaneous coronary intervention. With reference to the Japanese median population density of 1,147 people/km2, patients were divided into 2 groups: rural (n=6,908) and urban (n=10,259). Compared with the urban group, median D2B time was longer (70 vs. 62 min; P<0.001) and the rate of achieving a D2B time ≤90 min was lower (70.7% vs. 75.4%; P<0.001) in the rural group. In-hospital mortality was lower for patients with a D2B time ≤90 min than >90 min, regardless of residential area, whereas multivariable analysis identified prolonged D2B time as a predictor of in-hospital death only in the rural group (adjusted odds ratio 1.57; 95% confidence interval 1.18-2.09; P=0.002). Importantly, the rural-urban disparity in in-hospital mortality emerged most distinctively among patients with Killip Class IV and a D2B time >90 min.

CONCLUSIONS

These data suggest that there is a substantial rural-urban gap in the prognostic significance of D2B time among STEMI patients, especially those with cardiogenic shock and a prolonged D2B time.