PCI vs. CABG in left main with multi-vessel coronary artery disease and diabetes: Case report

Abstract

This case challenges the conventional preference for coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI) in patients with diabetes, left main coronary artery disease (LMCAD) and multivessel disease. Current guidelines generally recommend CABG, especially in the context of LMCAD. However, our case involves a male patient with diabetes with LMCAD and extensive multivessel disease who was successfully treated with PCI, demonstrating a favorable outcome. Despite the high-risk profile, including a SYNTAX score of 28, the PCI approach was selected. This decision was supported by evidence suggesting comparable outcomes between PCI and CABG in similar patients. Our case highlights the potential of PCI as not just a viable, but potentially superior alternative in specific high-risk patients with diabetes, contrary to the prevailing belief in favor of CABG for all patients with left main involvement.

Learning objectives

• Understand the decision-making process in choosing between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for patients with diabetes, left main coronary artery disease (LMCAD) and multivessel disease.

• Evaluate the outcomes and implications of using PCI over CABG in high-risk patients with diabetes with extensive coronary artery disease, particularly in the context of current medical guidelines and literature.

Introduction

In individuals suffering from stable ischemic heart disease coupled with significant left main coronary artery disease (LMCAD), current guidelines strongly endorse the use of coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI), receiving a class I recommendation status. ¹ This preference for CABG is widely adopted within the medical community, evidenced by a study examining LMCA cases from 2008 to 2020, which highlighted an approximately 17-fold greater inclination towards choosing CABG over PCI. ² The prevailing research consistently supports the choice of CABG for patients with isolated LMCA. Additionally, this preference extends to patients with multi-vessel disease not involving the LMCA, where CABG is favored over PCI. ³ Furthermore, in patients with non-LMCA multi-vessel disease who also have diabetes, outcomes are reportedly better with CABG than with PCI. ⁴

The clarity of these recommendations, however, diminishes when considering patients who have isolated LMCAD along with diabetes mellitus (DM). A systematic review posits that over a 5-year period, PCI’s effectiveness is comparable to that of CABG, particularly in terms of all-cause mortality. ⁵ The EXCEL trial also found no substantial differences in outcomes at 30 days and 3 years between CABG and PCI. ⁶ Currently, there are no randomized controlled trials (RCTs) specifically comparing CABG and PCI in this patient demographic. As such, the current guidelines offer a class 2b recommendation, acknowledging PCI as a viable and safe alternative to CABG, especially given the lack of discernible differences in 36-months survival rates among high-risk patients.^1,7 Unfortunately, the absence of RCTs directly contrasting CABG and PCI in patients with LMCAD and DM persists.

The situation becomes even more complex when high-risk patients with diabetes present with LMCA and multi-vessel disease. We discuss a case involving a patient with this specific medical profile, aiming to shed light on our decision-making process in such a scenario, where guidelines offer limited direction.

Case description

A 75-year-old male patient with a medical history of diabetes and a smoking history of 30 pack-years presented to the emergency department with symptoms of altered mental status, persistent vomiting, and diarrhea that had persisted for 1 day. Upon evaluation, the patient was found to be hypotensive, with a systolic blood pressure in the 70 mmHg range. The physical examination revealed a patient in moderate distress, responsive to voice but appearing drowsy. Additionally, the patient exhibited dry, cool, pale skin, and dry mucous membranes, but no other significant findings were noted.

Laboratory investigations (Table 1) were significant for leukocytosis, acute kidney injury (AKI), hyperglycemia, and lactic acidosis with an elevated anion gap. An arterial blood gas analysis showed a pH of 6.818, pCO2 level of 21.3 mmHg, and an pO2 level of 119 mmHg which confirms severe metabolic acidosis with inadequate respiratory compensation. In response to these findings, the patient was administered normal saline at a high rate, broad-spectrum antibiotics in line with sepsis protocol, including vancomycin and piperacillin-tazobactam, and intravenous insulin for treatment of diabetic ketoacidosis (DKA) protocol. Ultimately, the patient had a poor response to fluid resuscitation and was started on norepinephrine.

Table 1.

Laboratory results on admission.

Labs on admission
Parameteres: Units	Patient Values	Reference range
WBC: ×10^9/L	30.9	4.0–11.0 ×10^9/L
Hgb: g/dL	12.9	13.5–17.5 g/dL
Hct: %	41.1	40–52 %
Platelet: ×10^9/L	487	150–400 ×10^9/L
Glucose: mg/dL	>600	70–99 mg/dL
BUN: mg/dL	48	8–20 mg/dL
Creatinine: mg/dL	1.68	0.6–1.2 mg/dL
EGFR: mL/min/1.73 m^2	42	90–120 mL/min/1.73 m^2
Sodium: mmol/L	135	135–145 mmol/L
Potassium: mmol/L	4.2	3.5–5.0 mmol/L
Chloride: mmol/L	95	95–105 mmol/L
CO2 mmol/L	21	23–29 mmol/L
Anion Gap: mmol/L	19	3–11 mmol/L
Calcium Level: mg/dL	8.4	8.5–10.2 mg/dL
Hgb A1C %	8.6	4.0–5.6 %
PT: seconds	10.9	11–13.5 seconds
INR: ratio	1	0.8–1.2
APTT: seconds	28.3	25–35 seconds
D-Dimer: ng/mL	4388	0–500 ng/mL
Fibrinogen: mg/dL	432	200–400 mg/dL
Lactic Acid: mmol/L	5	0.5–2.2 mmol/L
HS Troponin-T: ng/L	1197	0–14 ng/L
HS Troponin-T 1hr: ng/L	1316	0–14 ng/L
HS Troponin-T 6hr: ng/L	7553	0–14 ng/L
1 hour delta	119	—
6 hour delta	6356	—
PBNP: pg/mL	21726	0–125 pg/mL

The initial high-sensitivity troponin level was notably elevated at 1197 ng/L, which was further supported by electrocardiogram findings of a first-degree atrioventricular block and ST depressions (Figure 1). A subsequent chest X-ray did not indicate any acute cardiopulmonary disease. A follow-up troponin measurement, taken 1 hour later, showed an increased level of 1316 ng/L. There was clear evidence of type 2 myocardial infarction due to multiple factors superimposed on top of cardiac ischemia. While managing DKA and sepsis was a priority, the team was also vigilant about the potential cardiac implications, given the troponins and NSTEMI findings on EKG.

Figure 1.

Electrocardiogram (EKG) on arrival.

The patient was urgently taken for cardiac catheterization, during which extensive multivessel disease was identified. Before revascularization could be attempted, the patient experienced a cardiac arrest triggered by sustained ventricular tachycardia. He was successfully resuscitated, mechanically ventilated, and converted back to sinus rhythm. Intravenous amiodarone was administered, and an intra-aortic balloon pump (IABP) was placed. The medical team prioritized stabilizing the patient and addressing his diabetic ketoacidosis (DKA) and septic shock before considering emergent revascularization.

Two days later, with the resolution of the patient’s comorbid conditions, a consultation with the cardiovascular surgery team was sought for a coronary artery bypass grafting (CABG) procedure. However, this option was declined due to the patient’s Society of Thoracic Surgeons (STS) risk of mortality score, which was calculated at 20%. Syntax score was 28. The decision to defer surgery was due to high risk of mortality given patients hemodynamic instability and multiple pathologies present. It was not based on the patient’s status of diabetes.

Subsequently, the interventional cardiology team successfully performed a multivessel percutaneous coronary intervention, placing a total of eight stents in the left anterior descending (LAD) artery, left circumflex (LCX) artery, and right coronary artery (RCA) (Figure 2). Following the procedure, the patient was gradually weaned off support systems and initiated on dual antiplatelet therapy (DAPT) and guideline-directed medical therapy (GDMT) for ischemic cardiomyopathy.

Figure 2.

RCA before (A) and after (B) PCI. LAD/LCX before (C), LCX before (D), LAD/LCX after (D) PCI.

The patient achieved hemodynamic stability and was successfully weaned off the ventilator, vasopressor support, and IABP. Repeat EKG on discharge with no ST depressions or signs of ischemia (Figure 3). Despite these advancements, he will be continuing his outpatient care in the Philippines, which makes long-term outcome monitoring challenging.

Figure 3.

Electrocardiogram (EKG) after PCI.

Discussion

Three critical decisions were pivotal in this case. First, we chose to delay the recommended revascularization for the initial 12 h to better stabilize the patient, enhancing the prospects of a successful revascularization. This decision was informed by literature indicating that postponing revascularization in patients with cardiogenic shock does not significantly increase mortality within the first 30 days. ⁸ Given the patient’s critical condition, this was a risk we deemed acceptable.

The second key decision involved the insertion of an intra-aortic balloon pump (IABP) as a temporary measure to stabilize the patient over a 48-h period. This strategy aimed to address the overlapping pathologies the patient was experiencing. Despite the lack of long-term mortality benefits associated with IABP, its use was crucial in our situation to gain time for treating the overlapping conditions before proceeding with emergent revascularization.^9,10

The third and final crucial decision was to proceed with high-risk multivessel percutaneous coronary intervention (MVPCI). The current literature suggests increased mortality associated with stenting multiple lesions compared to treating only the culprit lesion in patients with STEMI, but there is lack of clarity in patients with NSTEMI, such as in this case. ¹¹ We believed that these decisions offered our patient the best possible outcome under the circumstances.

Our patient had a SYNTAX score of 28, reinforcing our decision based on the findings from the SYNTAX and EXCEL trials. These trials indicate no significant mortality difference between PCI and CABG in patients with a SYNTAX score below 33. This is particularly relevant for patients with diabetes and with multivessel disease, especially when they are high-risk surgical candidates.^12,13

Conclusion

In the context of patients with diabetes, LMCA and multivessel disease, the choice between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) remains a complex and debated issue. The lack of literature requires the need for more randomized controlled trials to conclusively determine the optimal revascularization strategy in this specific patient population. Most importantly, while the early success with PCI in this case is noteworthy, it’s not intended to advocate for PCI over CABG in all such cases. We acknowledge the benefits of CABG in reducing long-term cardiac events.