Blood Pressure TTR Predicts Cardiovascular Outcomes in Diabetes

Researchers published the study covered in this summary on Research Square as a preprint that has not yet been peer reviewed.

Key Takeaways

• Increased time in target range (TTR) for systolic blood pressure predicted a decreased risk of a composite cardiovascular outcome (nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death) in patients with type 2 diabetes and hypertension in the Action to Control Cardiovascular Risk in Diabetes Blood Pressure (ACCORD BP) trial.

• The reduced risk of this primary outcome was similar in patients with a target systolic blood pressure of 120 to 140 mmHg (standard therapy group) or 110 to 130 mmHg (intensive therapy group).

Why This Matters

• Blood pressure control is an effective and practical way to reduce cardiovascular risk in patients with type 2 diabetes; however, blood pressure fluctuates continuously, so a single blood pressure reading from a clinic visit may not provide a true picture.

• TTR, on the other hand, reflects both average blood pressure and degree of fluctuation, and it may provide a more accurate picture of blood pressure control and may be a better way to determine if antihypertensive medications need to be adjusted.

 Study Design

• A secondary analysis of 2882 participants in the ACCORD blood pressure trial who had type 2 diabetes and hypertension (systolic blood pressure 130 to 180 mmHg) were randomized to receive intensive or standard blood pressure-lowering therapy.

• In the standard therapy group, blood pressure was measured at month 0 and every 4 months until study end. In the intensive therapy group, blood pressure was measured once a month for 4 months, and then every 2 months until study end.

• Secondary outcomes included all-cause mortality, cardiovascular death, chronic heart failure, nonfatal myocardial infarction, and total stroke.

Key Results

• Patients were a mean age of 63; 49% were women, 34% were Black, and 34% had cardiovascular disease at baseline.

• During exposure time (0 to 4 months), in the standard and intensive therapy groups, mean systolic blood pressure was 140 mmHg and 131 mmHg (P < .001) and the variability was by 12.3 mmHg versus 13.6 mmHg (P < .001).

• TTR was similar in the standard and intensive therapy groups (45.9% vs 45.6%; P = .76), and so the two groups were combined to maximize statistical power.

• Systolic blood pressure was in the target range:

  • < 25% of the time in 31% of patients

  • 25% to < 50% of the time in 21% of patients

  • 50% to < 75% of the time in 23% of patients

  • 75% to 100% of the time in 25% of patients 

• During a mean follow-up of 5 years, the primary outcome occurred in 280 participants.

• A 1-unit standard deviation increase in TTR was associated with decreased risks of the primary outcome (hazard ratio [HR], 0.83; P = .0026), all-cause mortality (HR, 0.83; P = .018), cardiovascular death (HR, 0.70; P = .0045), and nonfatal myocardial infarction (HR, 0.85; P = .034), all after adjusting for sex, age, Black race, education, glycemia group, blood pressure group, smoking status, baseline cardiovascular disease history, body mass index, A1c, total cholesterol, estimated glomerular filtration rate, and baseline systolic blood pressure.

• Systolic blood pressure TTR had a greater effect on outcomes in thinner participants (BMI ≤ 30 kg/m² vs > 30 kg/m²).

Limitations

• This was a secondary analysis of systolic blood pressure TTR and outcomes based on data from the ACCORD BP trial, which was not originally designed to examine this.

• There is no consensus about the optimal systolic blood pressure target ranges for patients with type 2 diabetes, so the chosen ranges may have introduced bias.

• The study estimated systolic blood pressure TTR during 4 months in the primary analyses and 8 months in further sensitivity analyses, which may have been too short.

Disclosures

• The study did not receive commercial funding.

• The authors have reported no relevant financial disclosures.

This is a summary of a preprint research study “Prognostic significance of systolic blood pressure time in target range in patients with type 2 diabetes mellitus” written by researchers from Shanghai Jiao Tong University School of Medicine, China. Preprints from Research Square are provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found on Research Square.

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