The incremental value of coronary artery calcium score in predicting long-term prognosis and defining the warranty period of normal adenosine stress-only myocardial perfusion imaging using CZT SPECT

BACKGROUND

Normal stress-only (SO) myocardial perfusion imaging (MPI) using SPECT reduces imaging time and radiation dose with a good prognosis. However, the long-term prognostic value of combining coronary artery calcium score (CACS) with SO MPI to determine the warranty period remains unknown. Hence, we assessed the incremental prognostic value of CACS and its impact on the warranty period of normal SO MPI using SPECT.

METHODS

We retrospectively included 1375 symptomatic patients without a history of coronary artery disease (CAD) and a normal SO MPI using adenosine who underwent simultaneous CAC scoring. Annual major adverse cardiac events (MACE) rates were calculated for CACS categories: 0, 1-399, 400-999, and ≥1000.

RESULTS

The mean age was 60.0 ± 11.8 years (66.9% female) with a median follow-up of 10.3 [IQR 9.6-10.9] years. The warranty period for annual MACE rate for normal SO SPECT extended the total follow-up time in years. MACE rate categorized by CAC categories demonstrated an increase in MACE rates with increasing CACS; CACS 0 and CACS 1-399 were associated with a 10-year warranty period, CACS 400-999 had a warranty period of 4 years and no warranty period could be given for CACS≥1000 (5.9 % at 1 year).

CONCLUSIONS

CACS as an adjunct to normal pharmacological SO MPI provides additional prognostic information and aids in determining a warranty period.

Prognostic value of myocardial perfusion scintigraphy in asymptomatic patients with diabetes mellitus at high cardiovascular risk: 5-year follow-up of the prospective multicenter BARDOT trial

Background

The Basel Asymptomatic High-Risk Diabetics’ Outcome Trial (BARDOT) demonstrated that asymptomatic diabetic patients with an abnormal myocardial perfusion scintigraphy (MPS) were at increased risk of major adverse cardiovascular events (MACEs) at 2-year follow-up. It remains unclear whether this finding holds true even for a longer follow-up.

Methods

Four hundred patients with type 2 diabetes, neither history nor symptoms of coronary artery disease (CAD), were evaluated clinically and with MPS. Patients were followed up for 5 years. Major adverse cardiovascular events (MACEs) were defined as all-cause death, myocardial infarction, or late coronary revascularization.

Results

At baseline, an abnormal MPS (SSS ≥ 4 or SDS ≥ 2) was found in 87 of 400 patients (22%). MACE within 5 years occurred in 14 patients with abnormal MPS (16.1%) and in 22 with normal scan (1.7%), p = 0.009; 15 deaths were recorded. Patients with completely normal MPS (SSS and SDS = 0) had lower rates of MACEs than patients with abnormal scans (2.5% vs. 7.0%, p = 0.032). Patients with abnormal MPS who had undergone revascularization had a lower mortality rate and a better event-free survival from MI and revascularization than patients with abnormal MPS who had either undergone medical therapy only or could not be revascularized (p = 0.002).

Conclusions

MPS may have prognostic value in asymptomatic diabetic patients at high cardiovascular risk over a follow-up period of 5 years. Patients with completely normal MPS have a low event rate and may not need retesting within 5 years. Patients with an abnormal MPS have higher event rates and may benefit from a combined medical and revascularization approach.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05349-5.

Time to and risk of cardiac events after myocardial perfusion scintigraphy

BACKGROUND

The burden of cardiovascular disease is increasing, yet it remains difficult to focus preventive strategies on populations at highest absolute and relative risks. We compared absolute and relative cardiovascular event counts, plus time to first event, among patients undergoing myocardial perfusion scintigraphy (MPS).

METHODS AND RESULTS

Our database was queried to identify subjects without myocardial necrosis or recent revascularization, focusing on cardiac death (CD) or myocardial infarction (MI). A total of 13,254 patients were included, 5436 (41%) without, and 7818 (59%) with ischemia. After 32±21 months, subjects without ischemia, compared to those with ischemia, had lower absolute (16 vs 75 events, 18% vs 82%, p<0.001) and relative (0.3% vs 1.3%, p<0.001) risk of CD. Similar findings were obtained for MI (52 vs 81 events, 39% vs 61%, p<0.001, with corresponding rates of 1.0% vs 1.4%, p<0.001, respectively). Medical therapy appeared associated with fewer outcomes in those without ischemia, with the opposite occurring for subjects with ischemia (p<0.001). Median times to event ranged between 13 and 25 months in patients without ischemia vs 2 and 14 months in those with ischemia (p<0.001 for all comparisons). Multivariable-adjusted and propensity matched analyses confirmed the independent prognostic role of myocardial ischemia and, apparently, revascularization.

CONCLUSION

Most fatal and non-fatal cardiac events appear to occur in patients with evidence of myocardial ischemia at MPS, especially those with moderate or severe ischemia not receiving revascularization during follow-up.