Introduction
The aim of the study was to evaluate the prognostic value of Killip classification in terms of health-related quality of life (HRQoL).
Methods
The sample consisted of 112 patients treated for myocardial infarction (MI), as onset manifestation of coronary artery disease (CAD), during 2008/09 in a prefectural hospital in northern Greece. At 1-year follow-up visit, HRQoL was measured using a generic and a disease-specific instrument. The 15D consists of a visual analogue scale (VAS) and a total score. The scoring algorithm of the MacNew generates a global score, and three separate domains scores: emotional, physical and social.
Results
Patients were grouped into the four Killip classes according to the degree of pulmonary congestion at admission (Table 1). Mean HRQoL for each group differed in the expected manner: the higher the class, the lower the HRQoL. Statistical significant differences were observed in VAS of the 15D and the emotional and social domain scores of the MacNew. Accordingly, the majority of patients with no signs of pulmonary congestion at admission were classified in NYHA functional class I at 1-year follow-up visit. No difference was observed in the type of MI, although patients in higher Killip classes had more affected arteries and were treated more often with CABG than PCI. Additionally, Killip class I patients were favored in a number of parameters including age, systolic blood pressure, heart rate, BMI, NT-proBNP level and LVEF.
Table 1.
Patient characteristics according to Killip classification
| Class I | Class II | Class III | Class IV | P value | |
|---|---|---|---|---|---|
| n (%) | 52 (46.4) | 40 (35.7) | 14 (12.5) | 6 (5.4) | NA |
| HRQoL (mean) | |||||
| 15D | |||||
| VAS | 78.9 | 76.9 | 72.9 | 70.8 | 0.025 |
| Total | 0.844 | 0.842 | 0.823 | 0.803 | 0.478 |
| MacNew | |||||
| Emotional | 5.60 | 5.61 | 5.38 | 5.05 | 0.030 |
| Physical | 5.49 | 5.26 | 5.25 | 5.05 | 0.144 |
| Social | 5.72 | 5.47 | 5.30 | 5.14 | 0.014 |
| Global | 5.52 | 5.44 | 5.27 | 4.98 | 0.056 |
| Age (years) | 61.8 | 66.0 | 70.2 | 61.2 | 0.013 |
| Gender (n, %) | |||||
| Male (85) | 40 (47.1) | 31 (36.5) | 12 (14.1) | 2 (2.4) | 0.080 |
| Female (27) | 12 (44.4) | 9 (33.3) | 2 (7.4) | 4 (14.8) | |
| ΒΜΙ | 28.7 | 29.1 | 30.0 | 34.8 | 0.001 |
| Systolic BP | 127.5 | 122.5 | 115.7 | 140.0 | 0.000 |
| Diastolic BP | 75.8 | 73.6 | 70.7 | 76.7 | 0.173 |
| Heart rate | 64.9 | 68.7 | 72.3 | 71.7 | 0.030 |
| CRP | 3.6 | 4.9 | 6.0 | 3.8 | 0.087 |
| NT-proBNP | 741 | 1645 | 2193 | 1674 | 0.000 |
| LVEF | 61.9 | 55.2 | 49.0 | 45.0 | 0.000 |
| MI type (n, %) | |||||
| STEMI (48) | 24 (50.0) | 18 (37.5) | 4 (8.3) | 2 (4.2) | 0.638 |
| NSTEMI (64) | 28 (43.8) | 22 (55.0) | 10 (15.6) | 4 (6.3) | |
| Affected arteries (n, %) | |||||
| 1 (38) | 19 (50.0) | 15 (39.5) | 4 (10.5) | 0 (0.0) | 0.005 |
| 2 (30) | 17 (56.7) | 9 (30.0) | 4 (13.3) | 0 (0.0) | |
| 3 (44) | 16 (36.4) | 16 (36.4) | 6 (13.6) | 6 (13.6) | |
| Revascularization technique (n, %) | |||||
| None (14) | 7 (50.0) | 3 (21.4) | 4 (28.6) | 0 (0.0) | 0.002 |
| PCI (63) | 35 (55.6) | 22 (34.9) | 6 (9.5) | 0 (0.0) | |
| CABG (35) | 10 (28.6) | 15 (42.9) | 4 (11.4) | 6 (17.1) | |
| ΝΥΗΑ | |||||
| Ι (73) | 42 (57.5) | 21 (28.8) | 8 (11.0) | 2 (2.7) | 0.013 |
| ΙΙ (37) | 8 (21.6) | 19 (51.4) | 6 (16.2) | 4 (10.8) | |
| ΙΙΙ (2) | 2 (100.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Rho | 0.28 | 0.001 | |||
Conclusion
Patients with MI as an onset manifestation of CAD present with varied degrees of pulmonary congestion. The prognostic value of the Killip classification is highlighted in terms of the extent of CAD (number of affected vessels and revascularization technique), of NYHA class and, last but not least, of HRQoL.