Process Standardization in High-Risk Coronary Interventions is Associated With Quality of Care Measures

Abstract

Background. Patient safety is one of the most important issues in healthcare. High-risk percutaneous coronary interventions (HR-PCIs) offer well-established treatment options for patients with complex coronary artery disease and multiple comorbidities. Whether process standardization using standard operating procedure (SOP) management and checklists improves HR-PCI is still unknown. Methods and Results. This retrospective study analyzed procedural characteristics, in-hospital outcomes, and length of hospital stay in patients who received HR-PCI in a German heart center 12 months before the introduction of process standardization using SOP management—the SOP (-) group—and after the introduction of process standardization using SOP management—the SOP (+) group. A total of 192 patients were included, with 77 patients in the SOP (-) group and 115 patients in the SOP (+) group. The mean age in the SOP (-) group was 72.0 ± 10.2 years and 81.8% were male; mean age in the SOP (+) group was 75.2 ± 10.4 years and 68.7% were male. Acute kidney events were significantly lower in the SOP (+) group than in the SOP (-) group (7.0% vs 10.4%; P=.04). Bleeding was the most common adverse event and significantly lower in the SOP (+) group than in the SOP (-) group (13.1% vs 31.2%, respectively; P<.01). There were trends toward shorter length of hospital stay in the SOP (+) group compared with the SOP (-) group (9.3 ± 6.4 days vs 10.9 ± 7.3 days, respectively; P=.10) and days of hospital stay in the intensive care unit (3.7 ± 4.0 days vs 4.7 ± 4.3 days; P=.07). SOP management was independently associated with shorter length of hospital stay in multivariate regression analysis. Conclusion. This retrospective study shows significantly better quality of care measures after the introduction of process standardization techniques using SOP management in HR-PCIs, with a lower risk of adverse outcomes and shorter length of hospital stay.

J INVASIVE CARDIOL 2022;34(10):E743-E749.

Key words: acute kidney injury, checklist, interventional cardiology, mortality, patient safety, process standardization, risk prediction bleeding, SOP management

The topic of patient safety in hospitals has been of particular importance since the publication of “To Err is Human” in 2000.¹ The demographic change in the patient population in hospitals has changed significantly in recent years, ie, elderly patients and patients with multiple comorbidities and a higher risk of complications receive medical treatment.^2-4 In addition, advances in medical technology as well as political and economic changes are leading to increasing levels of service compression and specialization in hospitals. This is due to the increasing complexity of the treatment cases.^5,6

Against this background, measures to improve patient safety in inpatient medical care have become of great importance. Standard operating procedure (SOP) management with the use of checklists is a sensible and proven technique for process standardization and optimization.^6,7 Based on an industrial model, the standardization of processes and the use of checklists to improve patient safety have been previously examined.^6,8 In the surgical discipline in particular, studies have assessed process optimization and its consequences for patient safety.^8,9 Typically, when evaluating interventions, reductions in complications and patient mortality were the primary endpoints assessed.^8,10

Coronary heart disease (CHD) is one of the leading causes of death worldwide.^4,11 Patients suffering from CHD are often older and have multiple comorbidities. In addition, CHD is often a multivessel disease.^2,12 Revascularization using percutaneous coronary intervention (PCI) or bypass surgery is an essential part of chronic CHD therapy.^13,14 Due to the high surgical risk of many patients with complex CHD, reduced left ventricular function, or severe comorbidity, high-risk (HR)-PCI offers an alternative to bypass surgery.^2,14-17 We hypothesized that process standardization using SOP management optimizes processes and increases patient safety in HR-PCIs, defined as reduced adverse outcomes and length of hospital stay.

Methods

Study design. This study was designed as a retrospective all-comer analysis of patients who underwent HR-PCI at the Düsseldorf Heart Center in 2017 and 2018. The results were assessed 12 months before and after the introduction of process standardization using SOP management. Patients who underwent HR-PCI in 2017 (before introduction of SOP management) were termed the SOP (-) group and were compared with those who underwent HR-PCI in 2018 (after introduction of SOP management), who were termed the SOP (+) group. The study was positively assessed by the ethics committee of Heinrich Heine University Düsseldorf (No. 6050R, Registration ID 2017074349).

Patient selection and data collection. Patient characteristics, details of clinical appearance and symptoms, comorbidities, characteristics of the catheterization procedures, other diagnostic tests (eg, routine blood laboratory, echocardiography), in-hospital adverse outcomes, and length of hospital stay were identified in medical records and collected in a database for further evaluation.

HR-PCI definitions. HR-PCI was defined as an elective or semielective coronary catheter intervention in patients at high interventional risk according to the following predefined criteria: complexity of coronary stenosis including left main stenosis; presence of left ventricular dysfunction; and cardiovascular and other comorbidities (Table 1). Patients with cardiogenic shock and acute coronary syndrome who required immediate coronary intervention were not included in the study. If 1 or 2 of the criteria for high interventional risk were met, the patient was classified at the HR 1 level. If 3 or more criteria were met or a patient suffered from a reduced left ventricular ejection fraction <35%, the patient was classified at the HR 2 level and peri-interventional mechanical hemodynamic support with a microaxial pump (Impella; Abiomed) was used. PCI was performed according to clinical practice recommended by guidelines.¹⁸

Process standardization using SOP management and checklist. Process standardization using SOP, including a checklist for management before and after the procedure, was introduced in 2018. Details are shown in Figure 1, Figure 2, and Figure 3.

Step 1: preprocedural management. Patient preparation was standardized, including blood analysis and blood group determination, dual-antiplatelet therapy (DAPT), groin and venous access preparation and planning of extracorporeal support, possible bailout strategies including surgery, and procedural preparation in the catheterization laboratory (Figure 3). All features of each patient’s medical history were discussed and included in the preparation. The team (both physicians and nurses) documented a review of key aspects of the patient during preparation on a checklist.

Step 2: postprocedural management. A re-evaluation of the decisions from step 1 was carried out. The focus was on patient aftercare, particularly on the assignment of the aftercare unit, including the aspects of extended monitoring or extended stay as well as postinterventional drug therapy.

Clinical outcome definitions. In-hospital clinical outcomes of mortality, bleeding and acute kidney injury (AKI) were assessed. Mortality was defined as postprocedural death during hospital stay. Bleeding events were defined using Bleeding Academic Research Consortium (BARC) criteria.¹⁹AKI was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.²⁰ The length of hospital stay and length of stay in intensive care were also assessed.

Statistical analysis. The statistical and graphical data analysis was carried out with Excel 2016 (Microsoft), SPSS 21.0 (IBM), and Graphpad Prism 8.0 (Graphpad Software). Continuous data with normal distribution (according to Shapiro-Wilk) are presented as means ± standard deviations (SD) and compared with a 2-sided Student’s t test. Non-normally distributed continuous data are presented as means with standard deviations and compared using Mann-Whitney U tests. Categorical data are presented as counts and percentages of totals and compared using Chi-squared and Fisher’s exact tests. Statistically significant differences in a test result were assumed at an alpha level of <.05.

Length of hospital stay, an important parameter of hospital treatment, was tested for associations with patient characteristics (age, sex), clinical characteristics (type of admission, heart failure), and SOP ± group assignment in univariate analysis and in Poisson multivariate regression analysis. Additionally, a negative binomial regression model with the same factors/covariates was tested to account for Poisson over dispersion.

Results

Patient characteristics. Baseline characteristics of patients are shown in Table 1. A total of 192 patients were included, with 77 patients in the SOP (-) group and 115 patients in the SOP (+) group. The mean age was significantly different between SOP (-) and SOP (+) groups, but sex was similar in both groups. Cardiovascular risk factors for arterial hypertension, diabetes mellitus, dyslipidemia, chronic kidney disease, vascular disease, and smoking history were common in both groups. Symptoms such as dyspnea (New York Heart Association classification) and angina pectoris (Canadian Cardiovascular Society classification) were also similar between groups. Preintervention risk assessment using the National Cardiovascular Data Registry (NCDR) risk models ​​showed similar mean mortality and bleeding risks.  There are 4 missing data in patient characteristics in the SOP (-) group and 2 missing data in the SOP (+) group.

Procedural characteristics. The distribution of HR levels was similar: HR level 1 was 78% in the SOP (-) group vs 77% in the SOP (+) group (P=.93) while HR level 2 was 22% in the SOP (-) group vs 23% in the SOP (+) group (P=.89).

The procedural duration was 76 minutes in the SOP (-) group vs 88 minutes in the SOP (+) group (P=.05). Multivessel PCI was performed in 15.6% of the SOP (-) group vs 23.5% of the SOP (+) group (P=.14). Radiation exposure time was significantly longer in the SOP (+) group vs the SOP (-) group (25 minutes vs 19 minutes, respectively; P<.01). The volume of applied contrast agent was similar between groups, with 179 mL utilized in the SOP (-) group vs 192 mL in the SOP (+) group (P=.29). The number of stents was also similar, at a mean of 1.7 in the SOP (-) group vs 1.9 in the SOP (+) group (P=.29). There are no missing data on procedural characteristics.

Clinical outcomes. Clinical outcomes are shown in Table 2 and Figure 4. Death rate during hospitalization was similar in both groups (2.6%; P=.99). AKI occurred significantly more frequently in the SOP (-) group vs the SOP (+) group (10.7% vs 7.0%, respectively; P=.04) (Figure 4A). Bleeding events were the most common adverse event in both groups, but significantly lower in the SOP (+) group vs the SOP (-) group (31.2% vs 13.0%, respectively; P<.01) (Figure 4B). The transfusion requirement in the SOP (-) group was only numerically higher vs the SOP (+) group, but the difference was not statistically significant (6.5% vs 3.5%, respectively; P=.33). There were no differences in length of hospital stay, which measured 10.9 ± 7.3 days in the SOP (-) group vs 9.3 ± 6.4 days in the SOP (+) group (P=.10) or in length of intensive care stay, which measured 4.7 ± 4.3 days in the SOP (-) group vs 3.7 ± 4.0 days in the SOP (+) group (P=.07).

There are no missing clinical outcomes data. In multivariate Poisson regression analysis, a longer length of hospital stay was associated with assignment to the SOP (-) group (P=.01), heart failure (P=.01), higher patient age (P<.01), and emergency admission (P<.01). Patient sex was not associated significantly; however, there was clear over-dispersion in the Poisson model. Negative binomial regression analysis (Table 3) then confirmed these results, with a longer length of hospital stay associated with assignment to the SOP (-) group (P<.01), heart failure (P=.02), higher patient age (P<.01), and emergency admission (P<.01); patient sex was not associated significantly.

Discussion

The present study analyzed clinical outcomes after implementation of process standardization using SOP management and checklists in patients undergoing HR-PCI. The main results are as follows: (1) SOP management for HR-PCI was significantly associated with fewer adverse outcomes regarding AKI and bleeding; and (2) SOP management was associated with length of hospital stay.

Process standardization using SOP management and checklists is defined as a written instruction of a process with different time periods in a complex system. SOPs and checklists lead to a standardization of processes that enables the maintenance of high quality in connection with a high level of patient safety, which is produced through greater efficiency.⁷ One of the first studies to describe the benefit of standardized procedures and checklists in the healthcare system was the 2006 Pronovost study, which found a reduction in the rate of catheter-associated sepsis.²¹ During surgical treatment, the use of process standardization also showed a reduction in the adverse outcome rate and postoperative mortality.^8,9,22 Particularly complex care structures, such as operating theaters and intensive care units, show an increased risk of errors and a loss of patient safety due to performance compression and increased patient turnover.⁷ The treatment of HR patients with PCI has a similarly complex care structure. Process standardization can be helpful to optimize the security structure. The patient population showed a typical composition of chronic CHD patients, ie, very high cardiovascular risk, advanced age, and male sex. Two-thirds of the patients underwent HR intervention in the HR 1 setting (high but not highest interventional risk), while the remaining one-third were in an HR 2 setting with Impella support (peri-interventional hemodynamic support). A relationship between the increased complexity of the interventions and a higher use of contrast media was observed. Despite the increased use of contrast media, AKI was lower in the SOP (+) group than in the SOP (-) group. We speculate that this effect could be linked to improved patient preparation or increased attention as a result of standardized patient care; for example, targeted volume therapy prior to PCI can prevent AKI. In addition to volume therapy, the use of protective PCI with Impella carriers (HR 2 setting) in patients with impaired left ventricular function and chronic kidney failure was discussed within the preparation. PCI with circulatory support leads to greater hemodynamic stability in the patient and can thus prevent acute kidney failure.²³

Another significant difference was the lower number of bleeding events in the SOP (+) group. Process standardization provides a standardized selection of patients with control of double platelet inhibition and risk stratification for bleeding complications. In addition, aftercare is considered under the auspices of bleeding risk. This factor, along with the consideration of a vascular closure system and intensive medical monitoring during a longer stay, are discussed and prepared, which may have helped to prevent bleeding events.

Further studies with larger patient cohorts are needed to determine the usefulness of a single factor. We also believe that process standardization will lead to greater awareness of HR patients among the team. Experienced and attentive staff are mandatory when caring for HR patients.¹² This can also have a positive effect on reducing adverse outcomes. Previous studies have shown that improving team communication has a positive effect on patient outcomes in operating rooms.^9,22 Nontechnical skills, such as communication, teamwork, leadership, and decision-making, seem to play a leading role in reducing the adverse outcome rate.¹⁰ In a review of the WHO checklists for surgery by Fudickar et al, the checklist was assessed as a tool that can improve communication, teamwork, and safety awareness during the operation.²⁴ In a 2015 overview by Bass et al, the importance of a multidisciplinary team for the safe implementation of HR-PCI was discussed.¹² We assume that the increased awareness of physicians and nurses in the care of HR patients via PCI has had a positive effect on patient outcomes.

Earlier studies have already shown that the length of stay can be shortened through improved processes, such as when performing colorectal surgery.²⁵ Appropriate intensive care capacity is essential for patient care and follow-up. These factors also have a positive effect on patient safety.⁷ Another analysis of our length of inpatient stay found a shorter inpatient stay within the SOP (+) group, which may have been a result of the lower adverse outcome rate within this group. In addition, there was a trend toward reduction of treatment duration in the intensive care unit of the SOP (+) group. The reduction in the duration of intensive care treatment despite the constant indication for postinterventional intensive care treatment and the more complex care situation of the SOP (+) group might also be due to the reduced adverse outcome rate in these patients. In addition to increasing quality during patient care, one goal of SOP is to increase efficiency from an economic point of view.⁷

Study limitations and strengths. The present study was limited by the retrospective character and time displacement of the SOP (-) and SOP (+) groups. The comparisons before and after introduction of the intervention do not allow us to conclude a causal association between intervention and outcomes, which would require an experimental design. Process evaluation was lacking. The focus of this study was also on examining the adverse outcomes during hospitalization and their outcomes. A longer view of the study cohort, including assessment of the patient’s viewpoint, was not carried out and would be required in further studies. Another limitation of the application of the negative binomial regression model is the lack of adjustment for dependency of hospital days per patient. However, the results were similar compared with linear models. Strengths of the study include a high documentation rate with few missing data (6 missing data in patient characteristics and no missing data in procedural data, adverse outcomes, and length of hospital stay).

Conclusion

This study shows significant positive associations between quality of care measures with the introduction of process-standardization techniques using SOP management in HR-PCIs, with a lower risk of adverse outcomes and associations with shorter length of hospital stay.

Affiliations and Disclosures

From the ¹Department of Internal Medicine, Division of Cardiology, Pulmonology and Vascular Medicine, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; ²CARID – Cardiovascular Research Institute, Düsseldorf, Germany; ³ Institute for Health Services Research and Health Economics, Centre for Health and Society, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany; and ⁴Institute for Health Services Research and Health Economics, German Diabetes Centre, Düsseldorf, Germany.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Jung reports consulting fees from Janssen, lecture fees from BMS, Edwards Lifesciences. Dr Wolff reports travel support for the ESC Congress from Abbott and Medtronic. The remaining authors report no conflicts of interest regarding the content herein.

The authors report that patient consent was provided for publication of the images used herein.

Manuscript accepted April 13, 2022.

Address for correspondence: Yvonne Heinen, MD, Department of Internal Medicine, Division of Cardiology, Pulmonology and Vascular Medicine, Heinrich-Heine-University, Moorenstr. 5, 40225 Düsseldorf, Germany. Email: yvonne.heinen@med.uni-duesseldorf.de

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