Effect of PM2.5 for hospitalization of cardiovascular diseases and medical expenses by age group: a nationwide study from the Japanese Registry Of All cardiac and vascular Diseases (JROAD)

Introduction

Although particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) exposure influences cardiovascular events, there is limited knowledge how PM2.5 exposure is associated with cardiovascular hospitalization in Japan.

Purpose

We tested the hypothesis that PM2.5 exposure was related to the number of cardiovascular hospitalizations, hospitalization period, and medical expenses.

Methods

We included 835,405 subjects who were admitted to acute care hospitals in Japan. We classified PM2.5 exposure concentration into quintile groups (from low to high in the order of “PM-1” to “PM-5” group). Multilevel mixed-effects Poisson and linear regression analysis were used to estimate the association of PM2.5 exposure concentration with the cardiovascular hospitalization events, duration and medical expenses. We also analyzed those factors classified by age.

Results

PM-2, 3, 4, 5 group were positively related to the number of cardiovascular hospitalization events compared with PM-1 group (Table 1). PM-3, 4, 5 group were positively associated with a 0.018, 0.029, and 0.029 (all p<0.001) of the difference of log cardiovascular hospitalization period compared with PM-1 group (p for trend <0.001). These groups were also positively associated with a 0.016, 0.023, and 0.021 (all p<0.001) of the difference of log medical expenses compared with PM-1 group (p for trend <0.001). Analyzed by age group, hospitalization duration was longer (p<0.05) and medical expenses was lower (p<0.05) significantly in super-aging group (over 90 years old) than the group under 64 years old (Figure 1).

Conclusions

PM2.5 exposure concentration has harmful effect on not only cardiovascular events but cardiovascular hospitalization period and medical expenses due to big-data in Japan. Medical costs were kept low in comparison with their hospitalization period in subjects over 90 years old.

Figure 1

Funding Acknowledgement

Type of funding source: None

Prognostic relevance of exercise pulmonary hypertension for new-onset atrial fibrillation in primary mitral regurgitation

Background/Introduction

New-onset of atrial fibrillation (AF) portends poor prognosis in patients with primary mitral regurgitation (MR). However less is known about prognostic indicator for new-onset AF.

Purpose

The purpose of this study was to identify the prognostic relevance of exercise pulmonary hypertension for the new-onset AF in patients with primary MR.

Methods

Total of 114 consecutive patients with primary MR who underwent symptom-limited exercise echocardiography using supine-cycle ergometer were followed for new-onset AF over mean follow-up time of 3.6±2.6 years. Those with prevalent AF and pulmonary hypertension (estimated systolic pulmonary artery pressure ≥50mmHg) prior to exercise echocardiography were excluded from our analysis. We defined exercise-induced pulmonary hypertension (ExPHT) as those with peak estimated systolic pulmonary artery pressure (SPAP) ≥60mmHg or delta SPAP defined as differences between rest and peak SPAP ≥20mmHg.

Results

The mean age was 61±15 years old and 70 (61%) were male. Of those, 8 (7.8%) had mild MR, 32 (31.1%) had moderate MR, and 63 (61.2%) had severe MR. 60 (52.2%) patients had ExPHT. A total of 27 cases of new-onset AF were found during follow-up where the ExPHT group had higher prevalence of new-onset AF than the non-ExPHT group (35% vs. 11%, p=0.002). Those with ExPHT had significantly stronger association with shorter event-free survival time of new-onset AF (log-rank p<0.001, Figure). When adjusted for age, sex, body surface area, the American Society of Echocardiography MR grade, left atrial dimension, peak systolic blood pressure and heart rate, the multivariable Cox regression analysis showed that those with ExPHT had a hazard risk of 3.1 ([95% CI 1.1–9.1], p=0.039) for new-onset of AF.

Conclusions

Exercise-induced pulmonary hypertension predicted incident of new-onset AF in those with primary MR. Exercise echocardiography is expected to play an important role in decision making with regards to the optimal timing for surgical intervention in primary MR.

Figure 1

Funding Acknowledgement

Type of funding source: None

P1493Prognostic significance of right ventricular function during exercise in patients with non-obstructive hypertrophic cardiomyopathy

Background

Hypertrophic cardiomyopathy (HCM) is a heterogeneous condition that may present crucial complication including life-threatening arrhythmia and sudden cardiac death. However, the risk stratification of HCM without left ventricular outflow tract (LVOT) obstruction had not been fully elucidated. Moreover, although recent studies have revealed the right ventricle (RV) involvement of HCM, the prognostic importance of RV function during exercise is unclear.

Purpose

To investigate the prognostic significance of RV function in patients with non-obstructive HCM using exercise stress echocardiography (ESE).

Methods and results

This study conducted on 100 HCM patients (age 62.9±13.6 years, 63% men) with preserved left ventricular ejection fraction who underwent ESE using semi-supine bicycle ergometer. Ten patients with significant LVOT obstruction (≥30mmHg) were excluded and 9 were also excluded because of the inadequate imaging quality or insufficiency of data. Among remaining 81 non-obstructive HCM patients, 9 patients suffered from HCM related cardiac events including cardiac death, unexpected hospitalization, life-threatening arrhythmias, and new-onset of syncope during the mean follow up period of 2.6±1.6 years. A multivariate Cox Hazard analysis revealed that low tricuspid annular plane systolic excursion during exercise (Ex-TAPSE, cut-off: 24mm) was an independent predictor of cardiac events. (hazard ratio: 18.66, 95% confidence interval: 3.66–338.46, P<0.001) The estimated cumulative cardiac event free survival using the Kaplan-Meier method was significantly lower in patients with reduced Ex-TAPSE (<24mm) than those with preserved Ex-TAPSE (Log-rank, P<0.01).

K-M curve according to Ex-TAPSE

Conclusion

Ex-TAPSE had a strong predictive value of clinical outcomes in non-obstructive HCM patients. Right ventricular function during exercise may have crucial role in the risk stratification of non-obstructive HCM.