Association Between Admission Blood Pressure and In-hospital Mortality and Long-term Mortality of Patients With ST-elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention: A China Acute Myocardial Infarction Registry Study.

BACKGROUND

Globally, acute myocardial infarction (AMI) is among the primary causes of mortality. The ideal approach for blood pressure (BP) management for patients experiencing ST-segment elevation myocardial infarction (STEMI) who receive percutaneous coronary intervention (PCI) remains a topic of ongoing debate. Current guidelines on BP management lack specific recommendations for STEMI patients undergoing PCI, resulting in substantial individual variability and uncertainties in clinical treatment strategies. This research seeks to determine the ideal BP levels linked to the lowest risk of in-hospital mortality and long-term adverse endpoints in STEMI patients receiving PCI.

METHODS

This retrospective study analyzed data from the China Acute Myocardial Infarction (CAMI) Registry, enrolling 10,482 STEMI patients undergoing PCI at 108 Chinese hospitals from January 2013 to September 2014. The primary outcome was in-hospital mortality. Secondary outcomes included 2-year all-cause mortality, severe bleeding, and major adverse cardiac and cerebrovascular events (MACCEs), defined as a combination of all-cause mortality, myocardial infarction (MI), or stroke. The analysis of the relationship between admission systolic blood pressure (SBP)/diastolic blood pressure (DBP) and the primary and secondary outcomes as continuous and categorical variables was conducted using restricted cubic spline (RCS) analysis and Cox regression models.

RESULTS

RCS analysis revealed that a J-shaped association existed between admission SBP/DBP and the risk of the primary outcome, with significant nonlinearity (both < 0.001). Both lower and higher SBP/DBP levels were linked to an elevated risk of in-hospital mortality. The ideal SBP/DBP levels to minimize the in-hospital mortality risk were 157/94 mmHg. Compared to the reference SBP/DBP group (120-129/70-79 mmHg), lower admission SBP (<109 mmHg) or DBP (60-69 mmHg) significantly elevated the risk of the primary outcome. The adjusted hazard ratio (HR) for SBP levels of 100-109 mmHg and <100 mmHg was 1.08 (95% confidence interval (CI): 1.00-1.17; = 0.0395 and = 0.043, respectively), and for DBP of 60-69 mmHg, the adjusted HR was 1.07 (95% CI: 1.01-1.14, = 0.0305). Similarly, the J-shaped curve was also noted between SBP/DBP and secondary outcomes, such as all-cause mortality, severe bleeding and MACCEs. However, no significant non-linear relationship was observed between SBP/DBP and recurrent MI at 2-year follow-up.

CONCLUSIONS

Among STEMI patients undergoing PCI, a J-curve relationship in in-hospital mortality was observed with a nadir at 157/94 mmHg. Similar J-shaped trends were also observed for secondary outcomes including all-cause mortality, severe bleeding and MACCEs. However, no significant nonlinear correlation was found between admission BP and recurrent MI within 2 years.

CLINICAL TRIAL REGISTRATION

NCT01874691, https://www.clinicaltrials.gov/study/NCT01874691?term=NCT01874691&rank=1.