Exhibit 99.31 MBNA MASTER CREDIT CARD TRUST II SERIES 1999-A KEY PERFORMANCE FACTORS April 30, 2001 Expected B Maturity 2/17/04 Blended Coupon 5.2913% Excess Protection Level 3 Month Average 7.67% April, 2001 7.51% March, 2001 8.08% February, 2001 7.42% Cash Yield19.61% Investor Charge Offs 4.98% Base Rate 7.13% Over 30 Day Delinquency 4.89% Seller's Interest 9.33% Total Payment Rate13.70% Total Principal Balance$58,171,313,434.78 Investor Participation Amount$500,000,000.00 Seller Participation Amount$5,425,622,873.29