Background: Resting coronary flow velocity (CFV) in the mid‐distal left anterior descending coronary artery can be easily assessed with transthoracic echocardiography. In this observational study, the authors sought to assess the relationship between resting CFV, CFV reserve (CFVR), and outcome in patients with chronic coronary syndromes. Methods and Results: In a prospective multicenter study design, the authors retrospectively analyzed 7576 patients (age, 66±11 years; 4312 men) with chronic coronary syndromes and left ventricular ejection fraction ≥50% referred for dipyridamole stress echocardiography. Recruitment (years 2003–2021) involved 7 accredited laboratories, with interobserver variability <10% for CFV measurement at study entry. Baseline peak diastolic CFV was obtained by pulsed‐wave Doppler in the mid‐distal left anterior descending coronary artery. CFVR (abnormal value ≤2.0) was assessed with dipyridamole. All‐cause death was the only end point. The mean CFV of the left anterior descending coronary artery was 31±12 cm/s. The mean CFVR was 2.32±0.60. During a median follow‐up of 5.9±4.3 years, 1121 (15%) patients died. At multivariable analysis, resting CFV ≥32 cm/s was identified by a receiver operating curve as the best cutoff and was independently associated with mortality (hazard ratio [HR], 1.24 [95% CI, 1.10–1.40]; P <0.0001) together with CFVR ≤2.0 (HR, 1.78 [95% CI, 1.57–2.02]; P <0.0001), age, diabetes, history of coronary surgery, and left ventricular ejection fraction. When both CFV and CFVR were considered, the mortality rate was highest in patients with resting CFV ≥32 cm/s and CFVR ≤2.0 and lowest in patients with resting CFV 2.0. Conclusions: High resting CFV is associated with worse survival in patients with chronic coronary syndromes and left ventricular ejection fraction ≥50%. The value is independent and additive to CFVR. The combination of high resting CFV and low CFVR is associated with the worst survival.

Aim: Coronary flow velocity (CFV) can be obtained with transthoracic echocardiography (TTE) in the left anterior descending coronary artery (LAD). The physiologic flow velocity gradient across the different segments of LAD has not been established. This study aims to assess the normal values of resting CFV in proximal, mid, and distal LAD. Methods: In a single center, prospective, observational study design, TTE was attempted on 110 consecutive, asymptomatic middle-aged subjects (age = 55 years, 46% males) with a low likelihood of coronary artery disease (< 5%). Resting CFV in the LAD was assessed with high-end machines, dedicated coronary pre-set, and high-frequency transducers by pulsed-wave Doppler under color-Doppler guidance in the proximal, mid, and distal segments. Results: The technical success rate for CFV imaging was lowest for the proximal (101/110, 92%), intermediate for mid (106/110, 96%), and highest for the distal segment (108/110, 98%). All 3 segments were interpretable in 101 subjects. CFV was highest in proximal segments (38.6 cm/s ± 3.9 cm/s), intermediate in mid segments (34.3 cm/s ± 6.04 cm/s, P < 0.01 vs. proximal), and lowest in distal segments (28.1 cm/s ± 1.7 cm/s, P < 0.01 vs. proximal and vs. mid). Conclusions: A resting evaluation of CFV-LAD can be obtained by TTE in the large majority of consecutive subjects referred to the echocardiography laboratory. Feasibility is highest for distal and lowest for proximal-LAD segments. There is a clear physiologic gradient of CFV with decreasing values, of about 10% for each step, going from proximal to mid and distal segments of LAD. When resting CFV is considered, the site of the sampling is important to obtain comparable and physiologically meaningful data.

Background/Objectives: Conventional cardiovascular risk scores may provide only modest discrimination in asymptomatic individuals undergoing screening. Ultrasound markers, including resting left anterior descending coronary artery peak diastolic flow velocity (V-LAD), carotid plaque, and global longitudinal strain (GLS), may detect subclinical abnormalities not captured by standard clinical assessment. Methods: In this prospective single-centre screening study, 1100 consecutive asymptomatic adults underwent clinical evaluation, laboratory testing, transthoracic echocardiography with coronary Doppler and GLS analysis, carotid ultrasound, and treadmill exercise electrocardiography. The primary analysis used Cox regression for time to the first composite event of adjudicated new-onset angina, acute coronary syndrome, heart failure hospitalization, atrial fibrillation, or death. Hierarchical models sequentially added continuous V-LAD, carotid plaque, and GLS to an internal clinical reference model. Results: Among 1094 evaluable participants, 79 primary endpoints occurred over a median follow-up of 25 months. Harrell C-index was 0.653 for the clinical model and increased to 0.824 after addition of V-LAD. The combined V-LAD-plus-plaque model had a C-index of 0.816, V-LAD was independently associated with outcome (HR 1.32 per + 10 cm/s (95% CI 1.23–1.43), p < 0.001) and carotid plaque remained strongly associated (HR 4.19 (95% CI 2.37–7.41), p < 0.001). Adding plaque beyond V-LAD significantly improved model fit (likelihood ratio p < 0.001) but did not further improve discrimination. GLS added no incremental prognostic information. Conclusions: V-LAD provided the major incremental gain in discrimination beyond conventional clinical variables, while carotid plaque contributed independent prognostic information and improved overall model fit without a consistent further gain in discrimination beyond V-LAD alone. GLS provided limited incremental value.