Although there was no association of reductions in average door-to-balloon (D2B) time and changes in mortality rate at the population level, many studies demonstrated that shorter patient-specific D2B times, directly associated with an amount of time the myocardial ischemia, were consistently associated with lower in-hospital mortality over time. Therefore, reducing D2B times should reduce the degree of myocardial ischemia and improve in-hospital mortality. To date, there are many barriers in the cardiac cath lab (i.e. on-time patient arrival, on-time physician arrival, on-time start, physician unavailability, pre-cath orders, and lab work) that cause delay procedure, leading to increased substantial morbidity and mortality in patients with ST elevation myocardial infarction (STEMI).

Lean and Six Sigma are strategies to reduce waste products and improve process efficiency and quality. Over the past decade, Lean and Six Sigma applications have been implemented in health care sector. In fact, the development of Lean started in the automobile industry (Toyota Production System), while Six Sigma was originally introduced by Motorola. Lean mainly targets a set of principles, practices and methods for designing, improving processes and reducing waste product, but is weak on organizational infrastructure and analytical tools. In contrast, Six Sigma is a business management strategy used to improve the quality and efficiency of an organizational infrastructure and provides statistical methods for problem solving. Although studies showed significant improvement in productivity and reductions in D2B times after Lean and Six Sigma implementations, Lean and Six Sigma applications have been underutilized in the cardiac cath lab. Ellahham et al. found that the implementation of the Lean Six Sigma methodology significantly reduced D2B time from 75.9 to 60.1 minutes (median) in patients with STEMI. In addition, the percentage of patients meeting the 90-minute window dramatically improved from 73% to 96%. Similarly, Kelly et al. have successfully applied Six Sigma in a tertiary care center and reduced D2B time for percutaneous coronary intervention (PCI) from 128 to 90 minutes. In addition, Yeh and colleagues demonstrated applying Lean Six Sigma methodology to reduce D2B time by 58.4%.

Other studies showed that the implementation of the Lean Six Sigma method was a significant improvement in productivity in the cardiac cath lab process. Agarwal et al. demonstrated that 3 years implementation of Lean Six Sigma implementation in the cardiac cath lab was a significant improvement in physician downtime, on-time patient arrival, on-time physician arrival, on-time start PCI and sheath-pulls inside cardiac cath lab. Pitta et al. showed that the implementation of Lean reduced time to schedule an appointment by 54% compared to pre intervention period. Overall, our brief review highlights the potential need for the implementation of Lean and Six Sigma methodology in the cardiac cath lab to reduce D2B times and improve productivity.